Undefeated rhymes with:
accreted, competed, depleted, maltreated, meted, mistreated, repeated, superheated, uncompleted, unseated, untreated
Undefeated sounds like:
undivided, undoubted, untapped
accreted, competed, depleted, maltreated, meted, mistreated, repeated, superheated, uncompleted, unseated, untreated
undivided, undoubted, untapped