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

A weight, power, or agency, acting against or balancing another

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

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

the arrangement of condition ordering for different subjects so that temporal and material effects are equally distributed over all conditions

A procedural step through which an experiment is arranged so that possible confounds will have an equal effect on all conditions, and thus cannot influence the comparison between conditions.

equality of distribution