necessity
n. C / Un. something that you must have or do in a particular situation. It is a basic need that you cannot live or work without.
n. the state or fact of being required or indispensable; a requirement that follows logically or legally from a set of conditions.
Water is a basic necessity for all living things.
The legal team argued that the breach of contract was a matter of necessity due to the sudden natural disaster.
While the initial investment seemed high, the upgrade was a strategic necessity to remain competitive in an increasingly digital global marketplace.
From Middle English necessite, from Old French necessite, from Latin necessitās (“unavoidableness, compulsion, exigency, necessity”), from necesse (“unavoidable, inevitable”); see necessary. Doublet of Necessitas.
Uncountable when referring to the abstract quality of being needed; countable when referring to specific required items or circumstances.
it is a necessity of doingit is a necessity to doWhen followed by an action, this noun typically takes a to-infinitive rather than a prepositional phrase.