necessity
/nɪˈsɛsəti/
The quality or state of being necessary, unavoidable, or absolutely requisite.
I bought a new table out of necessity. My old one was ruined.
The condition of being needy; desperate need; lack
Something necessary; a requisite; something indispensable.
A tent is a necessity if you plan on camping.
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.
Greater utilitarian good; used in justification of a criminal act.
doctrine of necessity
(in the plural) Indispensable requirements (of life).