initialism

An initialism is an abbreviation formed from the initial letters of a phrase, where each letter is pronounced individually. For example, FBI (Federal Bureau of Investigation) and YMCA (Young Men's Christian Association) are initialisms. This is distinct from an acronym, which is also formed from initial letters but is pronounced as a word, such as NASA or NATO. While some people strictly differentiate between the two, the term "acronym" is often used broadly to encompass both initialisms and pronounceable acronyms. Initialisms are generally older than acronyms, with the term "initialism" dating back to the mid-1800s, while "acronym" emerged around the 1940s.1234