absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"絶対に必要なさま須要
例:funds essential to the completion of the project プロジェクトの完成に不可欠な基金
basic and fundamental; "the essential feature"基本的な須要
例:The essential feature. 本質的特徴。
of the greatest importance; "the all-important subject of disarmament"; "crucial information"; "in chess cool nerves are of the essence"最も大きな重要性の至要たる
anything indispensable; "food and shelter are necessities of life"; "the essentials of the good life"; "allow farmers to buy their requirements under favorable conditions"; "a place where the requisites of water fuel and fodder can be obtained"不可欠な何でも必須