competition vs enemy

competition and enemy both are nouns.

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

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

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