equilibriumn.[L. aequilibrium, fr. 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.()Equilibrium valve (Steam Engine), a balanced valve. See under Valve.()