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
Antonyms: inessential, nonessential
Definition: anything that is not essential
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
Antonyms: procedural, adjective
Definition: relating to court practice and procedure as opposed to the principles of law
Main entry: essential
Definition: basic and fundamental
Usage: the essential feature
Antonyms: unessential, inessential
Definition: not basic or fundamental
Antonyms: secondary
Definition: being of second rank or importance or value; not direct or immediate
Antonyms: unconstitutional
Definition: not consistent with or according to a constitution; contrary to the U.S. Constitution
Antonyms: unstaple
Definition: take the staples off
Antonyms: procedural, adjective
Definition: relating to court practice and procedure as opposed to the principles of law
Antonyms: functional
Definition: involving or affecting function rather than physiology
Antonyms: inorganic
Definition: relating or belonging to the class of compounds not having a carbon basis
Antonyms: inorganic
Definition: lacking the properties characteristic of living organisms
Antonyms: insubstantial, unreal, unsubstantial
Definition: lacking material form or substance; unreal
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
Antonyms: unnecessary, unneeded
Definition: not necessary
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
Antonyms: unimportant
Definition: not important