opponent

noun

1. a person who is on an opposing side in a game, contest, controversy, or the like; adversary.

adjective

2. being opposite, as in position.
3. opposing; adverse; antagonistic.
4. Anatomy. bringing parts together or into opposition, as a muscle.

noun

1. a person who opposes another in a contest, battle, etc
2. anatomy an opponent muscle

adjective

3. opposite, as in position
4. anatomy (of a muscle) bringing two parts into opposition
5. opposing; contrary

n.1580s, from Latin opponentem (nominative opponens), present participle of opponere “oppose, object to,” literally “set against, set opposite,” from ob “against” (see ob-) + ponere “to put, set, place” (see position).