Merriam-Webster Collegiate Dictionary - opposite

 I. adjective  Etymology: Middle English, from Middle French, from Latin oppositus, past participle of opponere  Date: 14th century  1.  a. set over against something that is at the other end or side of an intervening line or space ~ interior angles ~ ends of a diameter  b. situated in pairs on an axis with each member being separated from the other by half the circumference of the axis ~ leaves — compare alternate  2.  a. occupying an opposing and often antagonistic position ~ sides of the question  b. diametrically different (as in nature or character) ~ meanings  3. contrary to one another or to a thing specified ; reverse gave them ~ directions  4. being the other of a pair that are corresponding or complementary in position, function, or nature members of the ~ sex  5. of, relating to, or being the side of a baseball field that is near the first base line for a right-handed batter and near the third base line for a left-handed batter  • ~ly adverb  • ~ness noun Synonyms:  ~, contradictory, contrary, antithetical mean being so far apart as to be or seem irreconcilable. ~ applies to things in sharp contrast or in conflict ~ views on foreign aid. contradictory applies to two things that completely negate each other so that if one is true or valid the other must be untrue or invalid made contradictory predictions about whether the market would rise or fall. contrary implies extreme divergence or diametrical opposition contrary assessments of the war situation. antithetical stresses clear and unequivocal diametrical opposition a law that is antithetical to the very idea of democracy.  II. noun  Date: 15th century  1. something that is opposed to some other often specified thing  2. antonym  3. additive inverse; especially the additive inverse of a real number  III. adverb  Date: 1667 on or to an ~ side  IV. preposition  Date: 1758  1. across from and usually facing or on the same level with sat ~ each other  2. in a role complementary to played ~ the leading man in the comedy