[化] 兴奋剂; 激动剂

[医] 主动肌, 主缩肌(与拮抗肌对立); 显效药, 促效药(与拮抗药对立)

1. the principal character in a work of fiction

<noun.person>

2. someone involved in a contest or battle (as in an agon)

<noun.person>

3. a muscle that contracts while another relaxes

<noun.body>
when bending the elbow the biceps are the agonist

4. (biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction

<noun.artifact>