front-runner vs competition

front-runner and competition both are nouns.

Word	Noun	Adjective	Verb	Adverb
front-runner	Yes	No	No	No
competition	Yes	No	No	No

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

Other hypernyms of front-runner include challenger, competitor, contender, rival.

front-runner (noun)	competition (noun)
a competitor thought likely to win	the act of competing as for profit or a prize
	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