Counterbalance

Pronunciation: -b?l"ans
v. t.

1. To oppose with an equal weight or power; to counteract the power or effect of; to countervail; to equiponderate; to balance.
   

Pronunciation: koun"t?r-b?l`ans
n.

1. 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
2. A counterpoise to balance the weight of anything, as of a drawbridge or a scale beam.