Retaliate, v. t. [imp. & p. p. Retaliated; p. pr. & vb. n. Retaliating.]
Etymology: [L. retaliatus, p. p. of retaliare to retaliate; pref. re- re- + a word akin to talio talion, retaliation. Cf. Talion.]
To return the like for; to repay or requite by an act of the same kind; to return evil for (evil). [Now seldom used except in a bad sense.] One ambassador sent word to the duke's son that his visit should be retaliated. Sir T. Herbert. It is unlucky to be obliged to retaliate the injuries of authors, whose works are so soon forgotten that we are in danger of appearing the first aggressors. Swift.
1 other Webster entry under this spelling
Retaliate, v. i.
To return like for like; specifically, to return evil for evil; as, to retaliate upon an enemy.
Shades of meaning
Fernald has no entry of its own for retaliate; he lists it under avenge, requite.
Where he writes about it:
To retaliate may be necessary for self-defense, without the idea of revenge. — from avenge
To repay or to retaliate, to punish or to reward, may be to make some return very inadequate to the benefit or injury received, or the right or wrong done; but to requite (according to its etymology) is to make so full and adequate a return as to quit oneself of all obligation of favor or hostility, of punishment or reward. — from requite