competitor vs rival

competitor and rival both are nouns.

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

As nouns, competitor and rival are synonyms defined as:

Other synonyms of competitor include challenger, competition, contender.

competitor (noun)	rival (noun)
the contestant you hope to defeat	the contestant you hope to defeat

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

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