ANTAG'ONIST, noun [Gr. against, and a champion. See Act and Agony.] 1. One who contends with another in combat; used primarily in the Grecian games. An adversary. 2. An opponent in controversy. 3. In anatomy, a muscle which acts in opposition to another; as a flexor, which bends a part, is the antagonist of an extensor, which extends it. ANTAG'ONIST, adjective Counteracting; opposing; combating; as, an antagonist muscle.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI