antagonistic has 4 distinct synonyms spread across 3 of its 5 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 2 recorded opposites are conciliatory, synergistic.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
indicating opposition or resistance
characterized by antagonism or antipathy
“slaves antagonistic to their masters”
arousing animosity or hostility
“his antagonistic brusqueness”
used especially of drugs or muscles that counteract or neutralize each other's effect
1 of the 5 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for antagonistic.
Synonyms, antonyms and the broader and narrower relations for antagonistic come from Princeton University’s WordNet. Full sources and licences.