covet vs envy

covet is not a noun while envy is a noun.

Word	Noun	Adjective	Verb	Adverb
covet	No	No	Yes	No
envy	Yes	No	Yes	No

As verbs, envy is a hypernym of covet; that is, envy is a word with a broader meaning than covet:

covet: wish, long, or crave for (something, especially the property of another person)
envy: be envious of; set one's heart on

Other hypernyms of covet include begrudge.

covet (noun)	envy (noun)
	spite and resentment at seeing the success of another (personified as one of the deadly sins)
	a feeling of grudging admiration and desire to have something that is possessed by another

covet (verb)	envy (verb)
wish, long, or crave for (something, especially the property of another person)	be envious of; set one's heart on
	feel envious towards; admire enviously