From WordNet (r) 3.0 (2006) [wn]:
counterattack
n 1: an attack by a defending force against an attacking enemy
force in order to regain lost ground or cut off enemy
advance units etc. [syn: counterattack, countermove]
2: (chess) an attack that is intended to counter the opponent's
advantage in another part of the board [syn: counterattack,
counterplay]
v 1: make a counterattack [syn: counterattack,
counterstrike]