noun
antagonist muscle; antagonistic muscle
Anatomical term for a muscle that opposes the action of another muscle (the agonist).
上腕二頭筋と上腕三頭筋は互いに拮抗筋の関係にある。
The biceps brachii and triceps brachii are antagonist muscles to each other.
Compound of 拮抗 (きっこう, 'rivalry, antagonism') and 筋 (きん, 'muscle').