pachyderm vs placental

pachyderm and placental both are nouns.

Word	Noun	Adjective	Verb	Adverb
pachyderm	Yes	No	No	No
placental	Yes	Yes	No	No

As nouns, placental is a hypernym of pachyderm; that is, placental is a word with a broader meaning than pachyderm:

pachyderm: any of various nonruminant hoofed mammals having very thick skin: elephant, rhinoceros, hippopotamus
placental: mammals having a placenta; all mammals except monotremes and marsupials

Other hypernyms of pachyderm include eutherian, eutherian mammal, placental mammal.

pachyderm (noun)	placental (noun)
any of various nonruminant hoofed mammals having very thick skin: elephant, rhinoceros, hippopotamus	mammals having a placenta; all mammals except monotremes and marsupials

pachyderm (adjective)	placental (adjective)
	pertaining to or having or occurring by means of a placenta