noun
counterblow; counterpunch
Used in boxing and combat sports for a punch thrown immediately after or in response to an opponent's attack.
彼は相手のジャブに合わせて強烈なカウンターブローを決めた。
He landed a powerful counterblow timed with his opponent's jab.
カウンター is a broader term for a counterattack or counterpunch, while カウンターブロー specifically refers to a counterblow (punch) in boxing.
Borrowed from English 'counterblow'.