cow vs placental mammal

cow and placental mammal both are nouns.

Word	Noun	Adjective	Verb	Adverb
cow	Yes	No	Yes	No
placental mammal	Yes	No	No	No

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

cow: mature female of mammals of which the male is called `bull'
placental mammal: mammals having a placenta; all mammals except monotremes and marsupials

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

cow (noun)	placental mammal (noun)
female of domestic cattle:	mammals having a placenta; all mammals except monotremes and marsupials
mature female of mammals of which the male is called `bull'
a large unpleasant woman

cow (verb)	placental mammal (verb)
subdue, restrain, or overcome by affecting with a feeling of awe; frighten (as with threats)