noun The quality or state of being necessary, unavoidable, or absolutely requisite.
I bought a new table out of necessity. My old one was ruined.
noun The condition of being needy; desperate need; lack.
noun Something necessary; a requisite; something indispensable.
A tent is a necessity if you plan on camping.
noun Something which makes an act or an event unavoidable; an irresistible force; overruling power.
After eating a full meal, the human body's necessity for food will compel the person to eat again in the future.
noun 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?)
noun Greater utilitarian good; used in justification of a criminal act.