mammal vs plantigrade

mammal and plantigrade both are nouns.

Word	Noun	Adjective	Verb	Adverb
mammal	Yes	No	No	No
plantigrade	Yes	Yes	No	No

mammal (noun)	plantigrade (noun)
any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk	an animal that walks with the entire sole of the foot touching the ground as e.g. bears and human beings

mammal (adjective)	plantigrade (adjective)
	(of mammals) walking on the whole sole of the foot (as rabbits, raccoons, bears, and humans do)