Some common synonyms of opposite are antithetical, contradictory, and contrary. While all these words mean "being so far apart as to be or seem irreconcilable," opposite applies to things in sharp contrast or in conflict.

// opposite views on foreign aid

The meanings of contrary and opposite largely overlap; however, contrary implies extreme divergence or diametrical opposition.

// contrary assessments of the war situation

The words contradictory and opposite can be used in similar contexts, but 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