Webster's Revised Unabridged Dictionary · 1913

Equilibrium

Equilibrium , noun

[Latin aequilibrium, from aequilibris in equilibrium, level; aequus equal + libra balance. See Equal, and Librate.]

1.
Equality of weight or force; an equipoise or a state of rest produced by the mutual counteraction of two or more forces.
2.
A level position; a just poise or balance in respect to an object, so that it remains firm; equipoise; as, to preserve the equilibrium of the body.
Health consists in the equilibrium between those two powers. — Arbuthnot
3.
A balancing of the mind between motives or reasons, with consequent indecision and doubt.
Collocations (1)
Equilibrium valve (Steam Engine) , a balanced valve. See under Valve.