fight has 18 distinct synonyms spread across 7 of its 9 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
a hostile meeting of opposing military forces in the course of a war
“Grant won a decisive victory in the battle of Chickamauga”
an aggressive willingness to compete
“the team was full of fight”
an intense verbal dispute
“a violent fight over the bill is expected in the Senate”
a boxing or wrestling match
“the fight was on television last night”
be engaged in a fight; carry on a fight
“the tribesmen fought each other”
Synonyms, antonyms and the broader and narrower relations for fight come from Princeton University’s WordNet. Full sources and licences.
fight against or resist strongly
“The senator said he would oppose the bill”