The definition of a necessity is something that is absolutely needed.
(noun)An example of a necessity is water for life.
See necessity in Webster's New World College Dictionary
noun pl. necessities
Origin: ME necessite < OFr nécessité < L necessitas < necesse: see necessary
See necessity in American Heritage Dictionary 4
noun pl. ne·ces·si·ties
Origin:
Origin: Middle English necessite
Origin: , from Old French
Origin: , from Latin necessitās
Origin: , from necesse, necessary; see necessary
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