What is the meaning of Necessity?

The quality or state of being necessary, unavoidable, or absolutely requisite.

The condition of being needy; desperate need; lack.

Something necessary; a requisite; something indispensable.

Something which makes an act or an event unavoidable; an irresistible force; overruling power.

The negation of freedom in voluntary action; the subjection of all phenomena, whether material or spiritual, to inevitable causation; necessitarianism. (Can we add an example for this sense?)

Greater utilitarian good; used in justification of a criminal act.

Indispensable requirements (of life).

Source: wiktionary.org