n. A weight, power, or agency, acting against or balancing another; as: (a) A mass of metal in one side of a driving wheel or fly wheel, to balance the weight of a crank pin, etc., on the opposite side of the wheel. (b) A counterpoise to balance the weight of anything, as of a drawbridge or a scale beam. [ 1913 Webster ]

Money is the counterbalance to all other things purchasable by it. Locke. [ 1913 Webster ]

v. t. [ imp. & p. p. Counterbalanced p. pr. & vb. n. Counterbalancing. ] To oppose with an equal weight or power; to counteract the power or effect of; to countervail; to equiponderate; to balance. [ 1913 Webster ]

The remaining air was not able to counterbalance the mercurial cylinder. Boyle. [ 1913 Webster ]

The study of mind is necessary to counterbalance and correct the influence of the study of nature. Sir W. Hamilton. [ 1913 Webster ]

adj. brought into equipoise by means of a weight or force that offsets another.
Syn. -- counterpoised. [ WordNet 1.5 ]