Antonyms of adj undefeated

1 sense of undefeated

Sense 1
undefeated (vs. defeated) -- (victorious; "undefeated in battle"; "an undefeated team")

defeated (vs. undefeated) -- (beaten or overcome; not victorious; "the defeated enemy")
        => licked -- (having been got the better of; "I'm pretty beat up but I don't feel licked yet")
        => subjugated -- (reduced to submission; "subjugated peoples")

Similarity of adj undefeated

1 sense of undefeated

Sense 1
undefeated (vs. defeated) -- (victorious; "undefeated in battle"; "an undefeated team")
       => triumphant, victorious -- (experiencing triumph)
       => unbeaten, unconquered, unvanquished -- (not conquered)
       => unbowed -- (not forced to bow down to a conqueror)
          Also See-> successful#1