competition vs foe

competition and foe both are nouns.

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

As nouns, foe is a hyponym of competition; that is, foe is a word with a more specific, narrower meaning than competition:

competition (noun)	foe (noun)
the act of competing as for profit or a prize	a personal enemy
an occasion on which a winner is selected from among two or more contestants	an armed adversary (especially a member of an opposing military force)
the contestant you hope to defeat
a business relation in which two parties compete to gain customers