Main entry: necessary, necessity, essential, requirement, requisite
Definition: anything indispensable
Usage: 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
Main entry: substantive, essential
Definition: defining rights and duties as opposed to giving the rules by which rights and duties are established
Usage: substantive law
Main entry: essential
Definition: basic and fundamental
Usage: the essential feature
Main entry: of the essence, essential, crucial, all important, all-important
Definition: of the greatest importance
Usage: the all-important subject of disarmament; crucial information; in chess cool nerves are of the essence
Main entry: indispensable, essential
Definition: absolutely necessary; vitally necessary
Usage: essential tools and materials; funds essential to the completion of the project; an indispensable worker
Main entry: essential
Definition: being or relating to or containing the essence of a plant etc
Usage: essential oil