herbivore vs brute

herbivore and brute both are nouns.

Word	Noun	Adjective	Verb	Adverb
herbivore	Yes	No	No	No
brute	Yes	Yes	No	No

As nouns, brute is a hypernym of herbivore; that is, brute is a word with a broader meaning than herbivore:

Other hypernyms of herbivore include animal, animate being, beast, creature, fauna.

herbivore (noun)	brute (noun)
any animal that feeds chiefly on grass and other plants	a living organism characterized by voluntary movement
	a cruelly rapacious person

herbivore (adjective)	brute (adjective)
	resembling a beast; showing lack of human sensibility