lemur: Lemur diversity: The gentle lemurs, or lesser bamboo lemurs (genus Hapalemur), and the highly endangered greater bamboo lemurs (Prolemur simus) feed on bamboo stems in the eastern and northwestern rainforests of the island.

crab: Distribution and variety: …food; another example is the coral-gall crab (Hapalocarcinidae), which irritates the growing tips of certain corals so that they grow to enclose the female in a stony prison. Many of the sluggish spider crabs (Majidae) cover their shells with growing seaweeds, zoophytes, and sponges, which afford them a very effective…

blue-ringed octopus, (genus Hapalochlaena), any of several Indo-Pacific octopus species known for their potent venom and their ability, when disturbed, to signal danger by flashing vivid blue rings or stripes in their skin. They can deliver a bite injecting the neurotoxin tetrodotoxin (TTX), which

blue-ringed octopus: Description and distribution: H. fasciata, the blue-lined octopus, measuring about 15 cm (5.9 inches) long, occurs in shallow coastal waters of Australia from southern Queensland to southern New South Wales. H. nierstraszi, which is about 8.2–16 cm (3.2–6.3 inches) long and weighs 5.5–18 grams (0.2–0.6 ounce), is known…

blue-ringed octopus: Description and distribution: H. lunulata, commonly called the greater blue-ringed octopus, is about 12 cm (4.7 inches) long and weighs about 55 grams (2 ounces) on average. It is found in shallow tidal pools, coral reefs, and reef flats around Indonesia, Papua New Guinea, the Philippines, Vanuatu, the…

blue-ringed octopus: Description and distribution: H. maculosa—the southern, or lesser, blue-ringed octopus—is about 22 cm (8.7 inches) long and weighs about 26 grams (0.9 ounce). It is found at depths of about 50 meters (160 feet) in the waters along Australia’s southern coastline and around Tasmania. H. fasciata, the blue-lined…

blue-ringed octopus: Description and distribution: H. nierstraszi, which is about 8.2–16 cm (3.2–6.3 inches) long and weighs 5.5–18 grams (0.2–0.6 ounce), is known from only two specimens. Both were recovered from the Bay of Bengal—one reported in 1938 along the coast of what is now Tamil Nadu, India, and the…

Ananse, name given to an Akan character who has become famous throughout Africa, the countries in the Caribbean region, and beyond because of his insight, intelligence, and wisdom. He is one of the most-important figures in the pantheon of cultural icons among West Africans. Along with his wife,

Apis, in ancient Egyptian religion, sacred bull deity worshipped at Memphis. The cult of Apis originated at least as early as the 1st dynasty (c. 2925–c. 2775 bce). Like other bull deities, Apis was probably at first a fertility god concerned with the propagation of grain and herds, but he became

altitude sickness: …serious type of altitude sickness, high altitude pulmonary edema (HAPE), occurs rarely among newcomers to altitude but more often affects those who have already become acclimated to high elevations and are returning after several days at sea level. In pulmonary edema, fluid accumulates in the lungs and prevents the victim…

Isabel Florence Hapgood was an American translator and writer, noted for making many classic Russian works available to an English-language audience for the first time. Hapgood studied foreign languages independently when her formal education ended in 1868, after three years at Miss Porter’s School

Hafṭarah, selective reading from Old Testament prophets recited in Jewish synagogues during the morning service on the sabbath and on festivals (but during the afternoon service on fast days). Though Haftarot vary with various rites and no longer follow recommendations of the Mishna (the lawbook

Hafṭarah, selective reading from Old Testament prophets recited in Jewish synagogues during the morning service on the sabbath and on festivals (but during the afternoon service on fast days). Though Haftarot vary with various rites and no longer follow recommendations of the Mishna (the lawbook

Apis, in ancient Egyptian religion, sacred bull deity worshipped at Memphis. The cult of Apis originated at least as early as the 1st dynasty (c. 2925–c. 2775 bce). Like other bull deities, Apis was probably at first a fertility god concerned with the propagation of grain and herds, but he became

Hapi, in ancient Egyptian religion, personification of the annual inundation of the Nile River. Hapi was the most important among numerous personifications of aspects of natural fertility, and his dominance increased during Egyptian history. Hymns were composed in his honour, but he had no temples

Moses: The date of Moses: …Habiru, a variant spelling of Ḫapiru (Apiru), a designation of a class of people who made their living by hiring themselves out for various services. The biblical Hebrews had been in Egypt for generations, but apparently they became a threat, so one of the pharaohs enslaved them. Unfortunately, the personal…

hapkido, a Korean form of unarmed self-defense based on the circular foot sweeps and kicks of traditional Korean tae kyon but incorporating punches and circular throws and a yielding principle similar to that of aikido. The emphasis on circular motion allows for a free-flowing form of combat in

mimicry: Mimicry within species: …cichlid fish of the genus Haplochromis. The female takes the eggs into her mouth immediately after they are laid, even before the male can fertilize them. The male, however, carries conspicuous yellow or orange spots near the base of the anal fin, which closely resemble the eggs of the particular…

animal social behavior: Social interactions involving cooperative breeding and eusociality: …a bizarre genetic system called haplodiploidy.

biblical literature: Problems visual in origin: Haplography, the accidental omission of a letter or word that occurs twice in close proximity, can be found, for example, in the Dead Sea Scroll text of Isaiah.

International HapMap Project: … through the development of a haplotype (haploid genotype) map of the human genome. A haplotype is a set of alleles (differing forms of genes) that occur close together on a single chromosome and tend to be inherited together. By identifying haplotypes and mapping their chromosomal locations, scientists are able to…

animal reproductive system: Parthenogenesis: …develop into haploid males (haploid parthenogenesis), which then participate in bisexual reproduction. Bisexually produced eggs are often referred to as winter eggs since they have a thick covering that protects the embryo during adverse environmental conditions. Summer eggs, produced parthenogenetically, are thin shelled. Bisexual reproduction occurs, therefore, only often…

algae: Reproduction and life histories: …of chromosomes and is called haploid, whereas in the second stage each cell has two sets of chromosomes and is called diploid. When one haploid gamete fuses with another haploid gamete during fertilization, the resulting combination, with two sets of chromosomes, is called a zygote. Either immediately or at some…

ploidy: This condition is called haploidy. When two germ cells (e.g., egg and sperm) unite, the diploid condition is restored.

linguistics: Sound change: …special case of dissimilation is haplology, in which the second of the two identical or similar syllables is dropped. Examples include the standard modern British pronunciations of “Worcester” and “Gloucester” with two syllables rather than three and the common pronunciation of “library” as if it were written “libry.” Both assimilation…

bryophyte: Annotated classification: Order Haplomitriales (formerly Calobryales) Leaves flattened and in three rows on an erect shoot arising from a colourless, subterranean, rootlike system that lacks rhizoids; sex organs lateral but near shoot apices; sporophytes with elongate seta; sporangium elongate, with elaters and thickenings on the jacket cell walls;…

bryophyte: Annotated classification: …Indo-Malayan region; 1 extant genus, Haplomitrium. Order Metzgeriales Thallose, with the thallus mainly of uniformly thickened cell walls, usually reclining but sometimes erect; branching varies from forked to regularly pinnate or irregular; smooth rhizoids on the undersurface; sex organs lateral; sporophytes with elongate seta; sporangia spherical to elongate, with elaters…

Sapindales: Distribution and abundance: Haplophyllum (about 70 species) occurs from the Mediterranean region to eastern Siberia.

branchiopod: Annotated classification: Infraorder Haplopoda Contains only 1 genus, Leptodora, a plankton feeder; carapace reduced to a dorsal brood pouch; large antennae with more than 20 swimming setae; 6 pairs of grasping trunk limbs; head elongated with small, complex eye; transparent except for eye; young develop into miniatures of…

primate: Classification: Suborder Haplorrhini 2 infraorders of 9 living families containing 41 living genera; 8 fossil families contain about 50 fossil genera dating to the Eocene. Infraorder Tarsiiformes 1 living family; included here are the Eocene to Early Miocene families Anaptomorphidae and Omomyidae. Family Tarsiidae

haplosporidian, any protozoan of the sporozoan subclass Haplosporea. They are internal parasites of invertebrates and lower vertebrates. Representative genera are Ichthyosporidium in fish, Coelosporidium in cockroaches, and the type genus Haplosporidium in annelids and other invertebrates.

haplosporidian, any protozoan of the sporozoan subclass Haplosporea. They are internal parasites of invertebrates and lower vertebrates. Representative genera are Ichthyosporidium in fish, Coelosporidium in cockroaches, and the type genus Haplosporidium in annelids and other invertebrates.

annelid: Annotated classification: Order Haplotaxida Chiefly aquatic worms; male gonopores in segment immediately behind testes; seminal receptacle at or near segment containing testes; size, minute to 1–3 cm; examples of genera: Nais, Tubifex (sludge worm). Class Hirudinea (leeches)

annelid: Annotated classification: …30–40 cm; examples of genera: Haplotaxis, Eisenia, Lumbricus (earthworm), Megascolides. Order Moniligastrida Male gonopores, 1 or 2 pairs on segment posterior to testes; clitellum 1 cell thick; 4 pairs of setae per segment; size, minute to 3 m; examples of genera:

International HapMap Project: … through the development of a haplotype (haploid genotype) map of the human genome. A haplotype is a set of alleles (differing forms of genes) that occur close together on a single chromosome and tend to be inherited together. By identifying haplotypes and mapping their chromosomal locations, scientists are able to…

pine: Physical description and natural history: …Pinus to contain two subgenera: Haploxylon, or soft pines, which have one fibrovascular bundle in the leaves, and Diploxylon, or hard pines, which have two. Soft pines, such as white, sugar, and piñon pines, have relatively soft timber, needles in bundles of five (less commonly, one to four), stalked cones…

Camille Lemonnier: Happe-Chair (1886), composed before but published after Zola’s Germinal, deals with the life of drudgery led by mill workers. Later, in the work of his middle period, Lemonnier turned to psychological analysis, condemning the conservative tendencies of the bourgeoisie. He then developed a mystical naturalism,…

Annie Ernaux: Film adaptations and Nobel Prize: Her work has been adapted to several award-winning films, including L’Evénement (2021; Happening), which won the Golden Lion at the 2021 Venice Film Festival.

Happening, event that combined elements of painting, poetry, music, dance, and theatre and staged them as a live action. The term Happening was coined by the American artist Allan Kaprow in the 1950s. The nature of Happenings was influenced by Italian Futurist performance, where the convention of

Faye Dunaway: …as her first two movies, The Happening and Hurry Sundown, were released early in 1967.

M. Night Shyamalan: String of duds and later revival: …Lady in the Water (2006), The Happening (2008), The Last Airbender (2010), and After Earth (2013), were widely panned by critics. The failure of The Last Airbender, an adaptation of the popular animated Nickelodeon series Avatar: The Last Airbender (2005–08), was particularly damaging to Shyamalan’s reputation, and it is often…

the Yardbirds: …one single, the visionary “Happenings Ten Years Time Ago” (1966), before the band’s short-lived final lineup dissolved in 1968.

Carol Shields: In Happenstance (1980) and A Fairly Conventional Woman (1982), Shields used overlapping narratives to escape the strictures of straightforward narrative told from a single perspective. Marketed in Canada as a crime drama, Swann: A Mystery (1987) is both a sly comedy of manners and a psychological…

Billie Eilish: When We All Fall Asleep, Where Do We Go? and Happier than Ever: …released her second studio album, Happier than Ever, which was noted for its confessional songs, a number of which deal with the downside of her celebrity.

Aubrey Plaza: Emily the Criminal and The White Lotus: …Mackenzie Davis in Clea DuVall’s Happiest Season, a comedy about two women struggling with their romantic relationship over the holidays. She then starred opposite Michael Caine in Best Sellers (2021) and played the titular role in Emily the Criminal (2022), about a young woman who turns to scamming to pay…

Agnès Varda: …Varda directed Le Bonheur (Happiness), an abstract picture of happiness and fidelity that was to be her most controversial film. Les Creatures (The Creatures) was released in 1966, and her most popular films of the next two decades were L’Une chante, l’autre pas (1977; One Sings, the Other Doesn’t)…

happiness, in psychology, a state of emotional well-being that a person experiences either in a narrow sense, when good things happen in a specific moment, or more broadly, as a positive evaluation of one’s life and accomplishments overall—that is, subjective well-being. Happiness can be

Jonas Brothers: …100 chart, and the album Happiness Begins (2019) topped the albums chart. Its popularity was aided by the release of the biographical documentary Chasing Happiness (2019).

Pipilotti Rist: …altered line from a Beatles song. By the late 1980s she was producing vivid and slickly made videos. In the 1990s she exhibited at a number of major venues, including the Museum of Contemporary Art in Chicago, the Stedelijk Museum in Amsterdam, and the National Gallery in Berlin. In 1998…

Lake Chūzenji, lake, lying within Nikkō National Park, Tochigi ken (prefecture), north-central Honshu, Japan. It is situated at an elevation of 4,163 feet (1,269 metres) and has a surface area of about 4.6 square miles (11.8 square km). Lake Chūzenji is a resort site noted for its shrines,

Pharrell Williams: Happy, G I R L, and other music projects: …had further success with “Happy,” an effervescent and infectious song that he had written for the animated film Despicable Me 2 (2013). It received an Academy Award nomination for best original song, and Williams performed it at the Oscar ceremony in 2014. His second solo album, G I R…

Beloved children’s author Beverly Cleary turned 100 on April 12, 2016. Once a children’s librarian, she turned her hand to writing in the 1940s, and her first book, Henry Huggins, was published in 1950. That book, and her subsequent body of work as a whole, became classic favorites of American

While Old Faithful in Yellowstone National Park is now considered a treasured U.S. landmark, in the 1800s some people viewed it quite differently—as a laundromat. Explorers and soldiers reportedly placed their clothing in Old Faithful, which would clean the garments when it erupted. In addition,

Vincent D’Onofrio: Roles in Law & Order: Criminal Intent and movies: …future, opposite Marisa Tomei, in Happy Accidents (2000); and embodied Abbie Hoffman in Steal This Movie (2000). In 2001 D’Onofrio began his 10-year run as the riveting central character, Detective Goren, in Law & Order: Criminal Intent.

Gregory Corso: In The Happy Birthday of Death (1960) he returned to an easier, conversational tone. Long Live Man (1962), Selected Poems (1962), The Mutation of the Spirit (1964), Elegiac Feelings American (1970), Herald of the Autochthonic Spirit (1981), and other books of poetry followed. In 1989 Corso…

Patty Smith Hill: …became the melody for “Happy Birthday to You.”

Kurt Vonnegut: Plays, later short stories, and nonfiction: …also wrote several plays, including Happy Birthday, Wanda June (1970; film 1971); several works of nonfiction, such as the collection Wampeters, Foma & Granfalloons (1974); and several collections of short stories, chief among which was Welcome to the Monkey House (1968). In 2005 he published A Man Without a Country:…

Mark Robson: Later films: …film, earned less attention, and Happy Birthday, Wanda June (1971) was a flawed adaptation of Kurt Vonnegut’s play, with Steiger as a big-game hunter who returns home after having been missing in the Amazon for eight years. The low-budget Limbo (1972) was notable for being among the first films about…

Lena Dunham: Later projects: …to mature in the comedy Happy Christmas (2014). In 2017 she joined Ryan Murphy’s anthology series American Horror Story for its seventh season (Cult); she portrayed Valerie Solanas, who shot Andy Warhol in 1968. Dunham later appeared in Quentin Tarantino’s Once Upon a Time…in Hollywood

Judith Leyster: …Carousing Couple (1630; also called The Happy Couple), and Boy Playing the Flute (c. 1635).

Samuel Beckett: Continuity of Beckett’s philosophical explorations: …the same human being? In Happy Days (1961), a woman, literally sinking continually deeper into the ground, nonetheless continues to prattle about the trivialities of life. In other words, perhaps, as one gets nearer and nearer death, one still pretends that life will go on normally forever.

Happy Days, American television situation comedy that aired on the American Broadcasting Company (ABC) network for 11 seasons (1974–84). The popular show achieved the number one Nielsen rating in its third season. Set in Milwaukee, Wisconsin, during the 1950s and ’60s, Happy Days presented an

Michael Haneke: …to the big screen with Happy End (2017), which he also wrote. The drama centres on a wealthy dysfunctional family in France.

Jean Simmons: …nomination, for best actress, for The Happy Ending (1969), written and directed by Brooks. Her other screen credits included Angel Face (1953), Guys and Dolls (1955), The Big Country (1958), Elmer Gantry (1960), Spartacus (1960), and

Carlos Fuentes: …Todas las familias felices (2006; Happy Families: Stories).

Savion Glover: …penguin Mumble in the computer-animated Happy Feet (2006) and Happy Feet Two (2011).

Savion Glover: …computer-animated Happy Feet (2006) and Happy Feet Two (2011).

Bob Barker: The Price Is Right and Happy Gilmore: …film debut in the comedy Happy Gilmore, in which he memorably fought Adam Sandler’s titular character.

Bad Bunny: 2026 Super Bowl performance and other projects: (2022), Cassandro (2023), and Happy Gilmore 2 (2025), and he directed a short film to accompany the album Debí tirar más fotos. Bad Bunny has frequently appeared on the sketch comedy show Saturday Night Live, beginning with a cameo in a 2020 episode, followed by his first gig as…

Curtis Bernhardt: Early years in Hollywood: …loan to Paramount, Bernhardt made Happy Go Lucky (1943), a pleasant though not very memorable musical featuring Dick Powell, Mary Martin, and Betty Hutton. Of more interest was the suspenseful Conflict (1945), which starred Humphrey Bogart in an overly contrived plot that nonetheless allowed Bernhardt to create moody visuals.

All eyes and ears turn to the furry forecaster. spotlight, holiday, american, tradition, groundhog, animal, superstition,

While now associated with costumes, trick-or-treating, and scary movies, Halloween wasn’t always a time of fun and games. The holiday had its origins in Samhain, one of the most-sinister festivals on the Celtic calendar. The ancient Celts believed that on November 1 the souls of those who had died

John Arden: The Happy Haven, produced in 1960 in London, is a sardonic farce about an old people’s home. The Workhouse Donkey is a crowded, exuberant, and comic drama of municipal politics. Armstrong’s Last Goodnight (1964) is a drama set in the Borders region of Scotland in…

What’s the Origin of Happy Hour?: Happy hour is an American tradition in which people gather at a local bar or restaurant (more or less between 3:00 and 6:00 pm) for discounted alcoholic beverages and appetizers. For many, it is also a time to congregate with friends or coworkers

the Who: …of Lily”), peer pressure (“Happy Jack”), creepy insects (Entwistle’s “Boris the Spider”), and gender confusion (“I’m a Boy”). As one instrument after another ended in splinters, the Who firmly declared themselves proponents of making violent rage a form of rock catharsis.

Irving Pichel: Directing: Happy Land (1943) starred Don Ameche in a sentimental yarn about a home-front tragedy during World War II, whereas And Now Tomorrow (1944) was sentiment sans patriotism, with Alan Ladd and Loretta Young playing would-be lovers whom society keeps apart.

Sukhavati, in the Pure Land schools of Mahayana Buddhism, the Western Paradise of the Buddha Amitabha, described in the Pure Land sutras (Sukhavati-vyuha-sutras). According to followers of the Pure Land schools, which are widespread throughout East Asia, rebirth in Sukhavati is ensured by invoking

Cesar Romero: …and with Sonja Henie in Happy Landing (1938) and Wintertime (1943). Romero was also featured in such musicals as The Great American Broadcast (1941), Weekend in Havana (1941), and Springtime in the Rockies (1942).

Tahar Ben Jelloun: …structured Le Bonheur conjugal (2012; The Happy Marriage) consists of an artist’s secret log of complaints about his wife and her responses when she finds it.

Factory Records: Manchester’s 24-Hour Party People: …arty mélange came Simply Red, the Happy Mondays, the Stone Roses, and the manic-depressive rants of the Smiths, though only the Happy Mondays recorded on Factory.

Oscar Wilde: Aestheticism, early writings, and marriage: …as a writer, he published The Happy Prince and Other Tales (1888), which reveals his gift for romantic allegory in the form of the fairy tale.

Colin Firth: Later credits: …friend of Oscar Wilde in The Happy Prince, and starred as an imperiled amateur sailor in The Mercy. Also that year he assumed the role of William Weatherall Wilkins, president of the Fidelity Fiduciary Bank, in Mary Poppins Returns. Firth then portrayed a British general in the World War I…

Bugs Bunny, cartoon rabbit created by Warner Brothers as part of its Looney Tunes animated short film series. Emerging as one of the biggest stars of the so-called golden age of American animation (1928–c. 1960), Bugs Bunny has endured as one of the world’s most popular cartoon characters. Bugs

Horatio Hornblower: The Hornblower novels begin with The Happy Return (1937; also published as Beat to Quarters) and conclude with the unfinished novel Hornblower and the Crisis (1967; also published as Hornblower During the Crisis and Two Stories: Hornblower’s Temptation and The Last Encounter). Other novels in the series include A Ship…

Jean-Pierre Cassel: …Gene Kelly discovered him for The Happy Road (1956). Later Cassel, a tall man with an expressive, mobile face, achieved fame as the comic protagonist in a series of films directed by Philippe de Broca. These included Les Jeux de l’amour (1960; The Love Game), Le Farceur (1960; The Joker),…

Robert Goulet: …performance in the Broadway musical The Happy Time. Although his popularity reached its zenith in the 1960s, his more than 60 albums, his film and TV appearances, and his work in Las Vegas nightclubs and in touring theatricals kept him busy for the rest of his career. Though his name…

the Turtles: …Be with Me” (1967), “Happy Together” (1967), their biggest hit, and “Elenore” and “You Showed Me” from the ambitious 1968 album The Turtles Present the Battle of the Bands.

Wong Kar-Wai: Chungwong chasit (1997; Happy Together) was filmed in Buenos Aires and was initially conceived as an adaptation of Manuel Puig’s detective novel The Buenos Aires Affair (1973). Happy Together chronicles the disintegrating love affair between two Hong Kong expatriates. Wong’s work on the film won him the award…

Roy Rogers: …off with the song “Happy Trails,” which Evans had written and which also became the title of their 1979 autobiography.

Patrick White: White’s first novel, Happy Valley (1939), was set in New South Wales and showed the influence of D.H. Lawrence and Thomas Hardy. The material of White’s later novels is distinctly Australian, but his treatment of it has a largeness of vision not limited to any one country or…

Happy Valley–Goose Bay, town, south-central Labrador, Newfoundland and Labrador, Canada, on the western end of Lake Melville and near the mouth of the Churchill River. Goose Bay was established in 1941 as a military and air ferrying base operated by the United States and Canada. By the Goose Bay

Reba McEntire: Acting and later music: She also starred in Happy’s Place (2024– ), playing a woman who inherits a bar. In addition, McEntire has guest roles on various TV series, and in 2019 she lent her voice to the animated film Spies in Disguise.

Mike Leigh: Happy-Go-Lucky (2008) presents the story of a free-spirited woman navigating the world around her, while Another Year (2010) follows a happily married couple and their less-sanguine family and friends. Both films earned Academy Award nominations for best original screenplay. In 2011 Leigh directed the Royal…

David Sedaris: …Diaries 2003–2020 (2021), he released Happy-Go-Lucky (2022), a volume of personal essays. In 2026 he followed up with the collection The Land and Its People; that year he also published the children’s book The Selfish Sister.

Melissa McCarthy: Roles from the late 2010s: …puppets in the screwball comedy The Happytime Murders. McCarthy also garnered critical acclaim—and her second Oscar nomination—for her sympathetic portrayal of disgraced celebrity biographer Lee Israel in Can You Ever Forgive Me? (2018). In The Kitchen (2019) McCarthy joined an all-star female cast playing a trio of mob wives who…

house of Habsburg, royal German family, one of the principal sovereign dynasties of Europe from the 15th to the 20th century. The name Habsburg is derived from the castle of Habsburg, or Habichtsburg (“Hawk’s Castle”), built in 1020 by Werner, bishop of Strasbourg, and his brother-in-law, Count

Buxales: …single species of the family Haptanthaceae, Haptanthus hazlettii, is a small tree native to Honduras; it is thought to be one of the rarest plants in the world. In 2010, after more than 20 years of unsuccessful attempts to relocate the plant based on two herbarium vouchers, the species was…

Buxales: …species of the family Haptanthaceae, Haptanthus hazlettii, is a small tree native to Honduras; it is thought to be one of the rarest plants in the world. In 2010, after more than 20 years of unsuccessful attempts to relocate the plant based on two herbarium vouchers, the species was rediscovered…

hapten, small molecule that stimulates the production of antibody molecules only when conjugated to a larger molecule, called a carrier molecule. The term hapten is derived from the Greek haptein, meaning “to fasten.” Haptens can become tightly fastened to a carrier molecule, most often a protein,

hapten, small molecule that stimulates the production of antibody molecules only when conjugated to a larger molecule, called a carrier molecule. The term hapten is derived from the Greek haptein, meaning “to fasten.” Haptens can become tightly fastened to a carrier molecule, most often a protein,