The Collaborative International Dictionary of English v.0.48:
Equilibrium \E`qui*lib"ri*um\, n.; pl. E. Equilibriums, L.
Equilibria. [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.
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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.
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Health consists in the equilibrium between those two
powers. --Arbuthnot.
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3. A balancing of the mind between motives or reasons, with
consequent indecision and doubt.
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Equilibrium valve (Steam Engine), a balanced valve. See
under Valve.
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