Coun·ter·vail v. t. [imp. & p. p. Countervailed p. pr. & vb. n. Countervailing.] To act against with equal force, power, or effect; to thwart or overcome by such action; to furnish an equivalent to or for; to counterbalance; to compensate.
Upon balancing the account, the profit at last will hardly countervail the inconveniences that go allong with it. --L'Estrange.