n. 25B6; noun
the world champion : WINNER, title-holder, defending champion, gold medallist; prizewinner, victor (ludorum); informal champ, number one.
a champion of change : ADVOCATE, proponent, promoter, supporter, defender, upholder, backer, exponent; campaigner, lobbyist, crusader, apologist; N. Amer. booster.
(historical) the king's champion : KNIGHT, man-at-arms, warrior.
25B6; verb championing the rights of tribal peoples : ADVOCATE, promote, defend, uphold, support, back, stand up for, take someone's part; campaign for, lobby for, fight for, crusade for, stick up for.
oppose.