competition vs contender

competition and contender both are nouns.

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

As nouns, competition and contender are synonyms defined as:

Other synonyms of competition include challenger, competitor, rival.

competition (noun)	contender (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