Synonyms for Champion (same or very similar meaning)
WordNet sense 1 (a person who backs a politician or a team etc.):
admirer, booster, friend, protagonist, supporter
WordNet sense 2 (someone who has won first place in a competition):
champ, title-holder
WordNet sense 3 (someone who fights for a cause):
fighter, hero, paladin
WordNet sense 4 (someone who is dazzlingly skilled in any field):
ace, adept, genius, hotshot, maven, sensation, star, superstar, virtuoso, whiz, whizz, wiz, wizard, mavin, adept
WordNet sense 5 (protect or fight for as a champion):
defend
WordNet sense 6 (holding first place in a contest):
prizewinning
From the ODE community, based on WordNet
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