adj Located directly across from something else, or from each other.
adj (botany) Of leaves and flowers, positioned directly across from each other on a stem.
adj Facing in the other direction.
adj Of either of two complementary or mutually exclusive things.
adj Extremely different; inconsistent; contrary; repugnant; antagonistic.
n Something opposite or contrary to something else.
n A person or thing that is entirely different from or the reverse of someone or something else; used to show contrast between two people or two things.
n An opponent.
n An antonym.
n (mathematics) An additive inverse.
adv In an opposite position.