antagonist

英 [æn'tæg(ə)nɪst] 美[æn'tæɡənɪst]

• n. 敌手；[解剖] 对抗肌；[生化] 拮抗物；反协同试剂

1. someone who offers opposition

2. a muscle that relaxes while another contracts;

"when bending the elbow the triceps are the antagonist"

3. a drug that neutralizes or counteracts the effects of another drug