pet vs brute

pet and brute both are nouns.

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

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

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

pet (noun)	brute (noun)
a domesticated animal kept for companionship or amusement	a living organism characterized by voluntary movement
a fit of petulance or sulkiness (especially at what is felt to be a slight)	a cruelly rapacious person
a special loved one

pet (adjective)	brute (adjective)
preferred above all others and treated with partiality	resembling a beast; showing lack of human sensibility

pet (verb)	brute (verb)
stroke or caress gently
stroke or caress in an erotic manner, as during lovemaking