favourite vs competitor

favourite and competitor both are nouns.

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

As nouns, competitor is a hypernym of favourite; that is, competitor is a word with a broader meaning than favourite:

Other hypernyms of favourite include challenger, competition, contender, rival.

favourite (noun)	competitor (noun)
something regarded with special favor or liking	the contestant you hope to defeat
a special loved one
a competitor thought likely to win

favourite (adjective)	competitor (adjective)
preferred above all others and treated with partiality
appealing to the general public

favourite (verb)	competitor (verb)
To mark an item as a personal favorite on social media