champion noun
ADJ. great, supreme, undisputed | defending, reigning The reigning champion will defend her title tonight. | former | national, world | Olympic the Olympic skating champion | boxing, snooker, etc.
VERB + CHAMPION become, be crowned He was crowned champion after his fight in Atlanta.
CHAMPION + VERB defend her/his title
CHAMPION + NOUN fighter, jockey, etc.
You can also check other dicts: champion (English, 中文解释 ), wordnet sense, Collins Definition