retaliate: [17] To retaliate is etymologically to give someone ‘so much’ or an equal amount in return for what they have given you. Its ultimate source is Latin tālis ‘suchlike’ (source of French tel ‘such’). This formed the basis of a noun tāliō ‘punishment equal in severity to the wrong that occasioned it’, which was combined with the prefix re- ‘back’ to create the verb retaliāre ‘repay in kind’ – whence English retaliate.
