champion vs whiz

champion and whiz both are nouns.

Word	Noun	Adjective	Verb	Adverb
champion	Yes	Yes	Yes	No
whiz	Yes	No	Yes	No

As nouns, champion and whiz are synonyms defined as:

Other synonyms of champion include ace, adept, genius, hotshot, maven, mavin, sensation, star, superstar, virtuoso, whizz, wiz, wizard.

champion (noun)	whiz (noun)
someone who fights for a cause	a buzzing or hissing sound as of something traveling rapidly through the air
someone who has won first place in a competition	someone who is dazzlingly skilled in any field
a person who backs a politician or a team etc.
someone who is dazzlingly skilled in any field

champion (adjective)	whiz (adjective)
holding first place in a contest

champion (verb)	whiz (verb)
protect or fight for as a champion	make a soft swishing sound