essential

1 essential /ɪˈsɛnʃəl/ adjective
1 essential
/ɪˈsɛnʃəl/
adjective
Britannica Dictionary definition of ESSENTIAL
[more essential; most essential]
1 
: extremely important and necessary
— often + to or for
— often followed by to + verb
— often + that
2 
: very basic : fundamental

— essentially

/ɪˈsɛnʃəli/ adverb [more essentially; most essentially]

— essentialness

/ɪˈsɛnʃəlnəs/ noun [noncount]
2 essential /ɪˈsɛnʃəl/ noun
plural essentials
2 essential
/ɪˈsɛnʃəl/
noun
plural essentials
Britannica Dictionary definition of ESSENTIAL
[count]
: something that is basic or necessary : something essential — usually plural