poikilotherm vs brute

poikilotherm and brute both are nouns.

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

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

poikilotherm: an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals
brute: a living organism characterized by voluntary movement

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

poikilotherm (noun)	brute (noun)
an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals	a living organism characterized by voluntary movement
	a cruelly rapacious person

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