agonist noun. ['agǝnɪst] E17.
[Greek agōnistēs contestant, formed as AGON: see -IST.]
1. A person who competes for prizes. rare. E17.

2. A protagonist in a drama (lit. & fig.). E20.

3. Physiology. A muscle whose contraction is directly responsible for the movement of a part. Cf. ANTAGONIST 2. E20.

4. Biochemistry. A chemical which combines with a receptor and initiates a physiological response. Cf. ANTAGONIST 3. M20.

[TahlilGaran] English Dictionary ▲