—necessariness, n./nes"euh ser'ee/, adj., n., pl. necessaries.adj.1. being essential, indispensable, or requisite: a necessary part of the motor.2. happening or existing by necessity: a necessary change in our plans.3. acting or proceeding from compulsion or necessity; not free; involuntary: a necessary agent.4. Logic.a. (of a proposition) such that a denial of it involves a self-contradiction.b. (of an inference or argument) such that its conclusion cannot be false if its supporting premises are true.c. (of a condition) such that it must exist if a given event is to occur or a given thing is to exist. Cf. sufficient (def. 2).n.5. something necessary or requisite; necessity.6. necessaries, Law. food, clothing, etc., required by a dependent or incompetent and varying with his or her social or economic position or that of the person upon whom he or she is dependent.7. Chiefly New Eng. a privy or toilet.[1300-50; ME necessarie < L necessarius unavoidable, inevitable, needful, equiv. to necess(e) (neut. indeclinable adj.) unavoidable, necessary + -arius -ARY]Syn. 1. required, needed. NECESSARY, ESSENTIAL, INDISPENSABLE, REQUISITE indicate something vital for the fulfillment of a need. NECESSARY applies to that without which a condition cannot be fulfilled or to an inevitable consequence of certain events, conditions, etc.: Food is necessary to life. Multiplicity is a necessary result of division.INDISPENSABLE applies to something that cannot be done without or removed from the rest of a unitary condition: Food is indispensable to living things. He made himself indispensable as a companion. That which is ESSENTIAL forms a vitally necessary condition of something: Air is essential to red-blooded animals. It is essential to understand the matter clearly. REQUISITE applies to what is thought necessary to fill out, complete, or perfect something: She had all the requisite qualifications for a position. 5. requirement, requisite, essential.Ant. 1. dispensable.
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