1 a an indispensible thing; a necessary (central heating is a necessity). b (usu. foll. by of) indispensability (the necessity of a warm overcoat).
2 a state of things or circumstances enforcing a certain course (there was a necessity to hurry).
3 imperative need (necessity is the mother of invention).
4 want; poverty; hardship (stole because of necessity).
5 constraint or compulsion regarded as a natural law governing all human action.
Phrases and idioms:
of necessity unavoidably.
Etymology: ME f. OF necessiteacute f. L necessitas -tatis f. necesse needful
Useful english dictionary. 2012.