being essential, indispensable, or requisite: a necessary part of the motor.
happening or existing by necessity: a necessary change in our plans.
acting or proceeding from compulsion or necessity; not free; involuntary: a necessary agent.
Logic.
(of a proposition) such that a denial of it involves a self-contradiction.
(of an inference or argument) such that its conclusion cannot be false if its supporting premises are true.
(of a condition) such that it must exist if a given event is to occur or a given thing is to exist.Compare sufficient (def. 2).
noun,pluralnec·es·sar·ies.
something necessary or required for a particular purpose; necessity.
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.
Chiefly New England. a privy or toilet.
Origin of necessary
First recorded in 1300–50; Middle English necessarie, from Latin necessārius “unavoidable, inevitable, needful,” equivalent to necess(e) (neuter indeclinable adjective) “unavoidable, necessary” + -ārius -ary
SYNONYMS FOR necessary
1 required, needed.
5 requirement, requisite, essential.
SEE SYNONYMS FOR necessary ON THESAURUS.COM
ANTONYMS FOR necessary
1 dispensable.
SEE ANTONYMS FOR necessary ON THESAURUS.COM
synonym study for necessary
1. Necessary,essential,indispensable,requisite indicate something vital for the fulfillment of a need. Necessary applies to something 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. Something that 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.
He could order the Justice Department to begin the necessary regulatory work.
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Yet, what my peers do not realize – or cannot handle – is that rejection is a necessary part of forging a romantic relationships.
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But as is her way, Kaling defended why the episode was not only funny, but necessary.
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Unfortunately, the underground tunnels that were used to transport booze and, if necessary, escaping patrons, are off-limits.
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However, we have just had a necessary wake-up call that all is not as secure as we believed.
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And this is all that is necessary as a preliminary to the discussion of just profits.
Distributive Justice|John A. (John Augustine) Ryan
As I have already said, we had made four oars, but our boat was so small that only two were necessary.
The Coral Island|R. M. Ballantyne
And considering the pressure of the necessary preparation for schools, the temptation to shun the byways is very great.
An American at Oxford|John Corbin
He denied that he was party to the attempt, and paid the necessary fee to the Hanaper for his pardon.
William de Colchester|Ernest Harold Pearce
He was aware that his speech was growing far louder than necessary.
Cytherea|Joseph Hergesheimer
British Dictionary definitions for necessary
necessary
/ (ˈnɛsɪsərɪ) /
adjective
needed to achieve a certain desired effect or result; required
resulting from necessity; inevitablethe necessary consequences of your action
logic
(of a statement, formula, etc) true under all interpretations or in all possible circumstances
(of a proposition) determined to be true by its meaning, so that its denial would be self-contradictory
(of a property) essential, so that without it its subject would not be the entity it is
(of an inference) always yielding a true conclusion when its premises are true; valid
(of a condition) entailed by the truth of some statement or the obtaining of some state of affairsCompare sufficient (def. 2)
philosophy(in a nonlogical sense) expressing a law of nature, so that if it is in this sense necessary that all As are B, even although it is not contradictory to conceive of an A which is not B, we are licensed to infer that if something were an A it would have to be B
rarecompelled, as by necessity or law; not free
noun
the necessaryinformalthe money required for a particular purpose
do the necessaryinformalto do something that is necessary in a particular situation
See also necessaries
Word Origin for necessary
C14: from Latin necessārius indispensable, from necesse unavoidable