COUNTERVAIL, verb transitive [counter and Latin , to avail or be strong.] To act against with equal force, or power; to equal; to act with equivalent effect against any thing; to balance; to compensate.

The profit will hardly countervail the inconveniences.

Although the enemy could not countervail the kings damage. Esther 7:4.

COUNTERVAIL, noun Equal weight or strength; power or value sufficient to obviate any effect; equal weight or value; compensation; requital.