"agonist" in the noun sense
1. protagonist, agonist
the principal character in a work of fiction
2. agonist
someone involved in a contest or battle (as in an agon)
3. agonist
a muscle that contracts while another relaxes
"when bending the elbow the biceps are the agonist"
4. agonist
biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License