competition vs rival

competition and rival both are nouns.

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

As nouns, competition and rival are synonyms defined as:

Other synonyms of competition include challenger, competitor, contender.

competition (noun)	rival (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

competition (adjective)	rival (adjective)
	as a rival in a competition

competition (verb)	rival (verb)
	be the rival of, be in competition with
	be equal to in quality or ability