D defs.my
Entry 3 senses Webster, 1913

Equilibrium

/ēkˌ-wəl-ĭb'-rē-əm/ · E·qui·lib·ri·um · IPA /ɛkwɪˈlɪbɹɪəm/
01 n. Equality of weight or force; an equipoise or a state of rest produced by the mutual counteraction of two or more forces.
pl. Equilibriums, Equilibria ((#))
  1. 1.
    Equality of weight or force; an equipoise or a state of rest produced by the mutual counteraction of two or more forces.
  2. 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. 3.
    A balancing of the mind between motives or reasons, with consequent indecision and doubt.
Phrases & compounds
Equilibrium valve — a balanced valve. See under Valve.