favourite vs competition

favourite and competition both are nouns.

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

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

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

favourite (noun)	competition (noun)
something regarded with special favor or liking	the act of competing as for profit or a prize
a special loved one	an occasion on which a winner is selected from among two or more contestants
a competitor thought likely to win	the contestant you hope to defeat
	a business relation in which two parties compete to gain customers

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

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