Countervail

v. t. [imp. & p. p. COUNTER-VAILED; p. pr. & vb. n. COUNTERVAILING.] [counter and Lat. valere, to be strong, to avail; O. Fr. contrevaloir, Pr. contravaler, It. contravvalere.] To act against with equal force, power, or effect; to thwart or overcome by such action; to furnish an equivalent to or for; to equal; to balance; to compensate.

We are to compute, that upon balancing the account, the profit at last will hardly countervail the inconveniences that go along with it. L'Estrange.