Pronunciation: (nu-ses'i-tē),[key] —n., —pl.-ties. 1. something necessary or indispensable: food, shelter, and other necessities of life. 2. the fact of being necessary or indispensable; indispensability: the necessity of adequate housing. 3. an imperative requirement or need for something: the necessity for a quick decision. 4. the state or fact of being necessary or inevitable: to face the necessity of testifying in court. 5. an unavoidable need or compulsion to do something: not by choice but by necessity. 6. a state of being in financial need; poverty: a family in dire necessity. 7. Philos.the quality of following inevitably from logical, physical, or moral laws.
8. of necessity, as an inevitable result; unavoidably; necessarily: Our trip to China must of necessity be postponed for a while.