counterpoise

From Old French contrepois, contrepeser, later assimilated to poise.

counterpoise (plural counterpoises)

1. A weight sufficient to balance another, as in the opposite scale of a balance; an equal weight.
2. An equal power or force acting in opposition; a force sufficient to balance another force.
3. The relation of two weights or forces which balance each other; equilibrium; equiponderance.

counterpoise (third-person singular simple present counterpoises, present participle counterpoising, simple past and past participle counterpoised)

1. To act against with equal weight; to equal in weight; to balance the weight of; to counterbalance.
   • 1655, Kenelm Digby, Two Treaties

     Weights, counterpoising one another.

2. To act against with equal power; to balance.
   • (Can we date this quote by Spenser?)

     So many freeholders of English will be able to beard and to counterpoise the rest.