championship vs contest

championship and contest both are nouns.

Word	Noun	Adjective	Verb	Adverb
championship	Yes	No	No	No
contest	Yes	No	Yes	No

As nouns, contest is a hypernym of championship; that is, contest is a word with a broader meaning than championship:

championship: a competition at which a champion is chosen
contest: an occasion on which a winner is selected from among two or more contestants

Other hypernyms of championship include competition.

championship (noun)	contest (noun)
the act of providing approval and support	a struggle between rivals
a competition at which a champion is chosen	an occasion on which a winner is selected from among two or more contestants
the status of being a champion

championship (verb)	contest (verb)
	to make the subject of dispute, contention, or litigation