|essential /ɪˈsɛnʃəl/ adjective|
comparative and superlative forms: more essential; most essential
1 : extremely important and necessary • As a fighter pilot, he knows that good vision is essential. • Reservations are essential[=necessary, needed] if you plan to eat there on a Saturday. — often followed by to or for • The river is essential to the region’s economy. • Food is essential [=necessary] for life. — often followed by to + verb • It is essential to use the proper technique. • It's essential to arrive on time. — often followed by that • It'sessential that we arrive on time.
2 : very basic : fundamental • Free speech is an essential right of citizenship. • The essential problem with this plan is that it will cost too much. • There's no essential difference between the two products.
— essentially /ɪˈsɛnʃəli/ adverb [more essentially; most essentially] • All action movies have essentially [=basically, fundamentally] the same plot.• What he says is essentially true.
— essentialness /ɪˈsɛnʃəlnəs/ noun [noncount]
Learn about essential as a noun.