counterattack has 3 distinct synonyms spread across 3 of its 3 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
an attack by a defending force against an attacking enemy force in order to regain lost ground or cut off enemy advance units etc.
(chess) an attack that is intended to counter the opponent's advantage in another part of the board
Synonyms, antonyms and the broader and narrower relations for counterattack come from Princeton University’s WordNet. Full sources and licences.