Placed or located directly across from something else or from each other: opposite sides of a building. Facing the other way; moving or tending away from each other: opposite directions. Being the other of two complementary or mutually exclusive things: the opposite sex; an opposite role to the lead in the play. Altogether different, as in nature, quality, or significance: The effect of the medication was opposite to that intended. Sharply contrasting; antithetical: had opposite views on the subject. Botany Growing in pairs on either side of a stem: opposite leaves. One that is opposite or contrary to another. An opponent or antagonist. An antonym. In an opposite position: They sat opposite at the table. Across from or facing: parked the car opposite the bank. In a complementary dramatic role to: He played opposite her.