conflict has 10 distinct synonyms spread across 4 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.
an open clash between two opposing groups (or individuals)
“the harder the conflict the more glorious the triumph”
opposition between two simultaneous but incompatible feelings
“he was immobilized by conflict and indecision”
a hostile meeting of opposing military forces in the course of a war
“Grant won a decisive victory in the battle of Chickamauga”
a state of opposition between persons or ideas or interests
“his conflict of interest made him ineligible for the post”
an incompatibility of dates or events
“he noticed a conflict in the dates of the two meetings”
opposition in a work of drama or fiction between characters or forces (especially an opposition that motivates the development of the plot)
“this form of conflict is essential to Mann's writing”
a disagreement or argument about something important
“he had a dispute with his wife”
go against, as of rules and laws
“He ran afoul of the law”
Synonyms, antonyms and the broader and narrower relations for conflict come from Princeton University’s WordNet. Full sources and licences.