adjective

1. set against, facing, or back to back; at the other end or side; in a contrary position or direction: often with to
2. characterized by hostility or resistance
3. different in every way; exactly contrary; antithetical
4. Bot.
   1. growing in pairs, but separated by a stem
   2. having one part on the same radius as another, as a stamen in front of a petal

Etymology: OFr < L oppositus, pp. of opponere: see opponent

noun

adverb

1. facing; across from
2. Theater in a complementary role (of the opposite sex) to he played opposite her