competition vs challenger

competition and challenger both are nouns.

Word	Noun	Adjective	Verb	Adverb
competition	Yes	No	No	No
challenger	Yes	No	No	No

As nouns, competition and challenger are synonyms defined as:

Other synonyms of competition include competitor, contender, rival.

competition (noun)	challenger (noun)
the act of competing as for profit or a prize	the contestant you hope to defeat
an occasion on which a winner is selected from among two or more contestants
the contestant you hope to defeat
a business relation in which two parties compete to gain customers