defeated has 5 distinct synonyms spread across 2 of its 3 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 one recorded opposite is undefeated.
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.
beaten or overcome; not victorious
“the defeated enemy”
disappointingly unsuccessful
“disappointed expectations and thwarted ambitions”
Synonyms, antonyms and the broader and narrower relations for defeated come from Princeton University’s WordNet. Full sources and licences.
people who are defeated
“the Romans had no pity for the defeated”