Necessity

1. The negation of freedom in voluntary action; the subjection of all phenomena, whether material or spiritual, to inevitable causation; necessitarianism.
2. That which is necessary; a necessary; a requisite; something indispensable; -- often in the plural.
3. That which makes an act or an event unavoidable; irresistible force; overruling power; compulsion, physical or moral; fate; fatality.
4. The quality or state of being necessary, unavoidable, or absolutely requisite; inevitableness; indispensableness.
5. The condition of being needy or necessitous; pressing need; indigence; want.