flying cat vs eutherian mammal

flying cat and eutherian mammal both are nouns.

Word	Noun	Adjective	Verb	Adverb
flying cat	Yes	No	No	No
eutherian mammal	Yes	No	No	No

As nouns, eutherian mammal is a hypernym of flying cat; that is, eutherian mammal is a word with a broader meaning than flying cat:

flying cat: arboreal nocturnal mammal of southeast Asia and the Philippines resembling a lemur and having a fold of skin on each side from neck to tail that is used for long gliding leaps
eutherian mammal: mammals having a placenta; all mammals except monotremes and marsupials

Other hypernyms of flying cat include eutherian, placental, placental mammal.

flying cat (noun)	eutherian mammal (noun)
East Indian flying squirrel	mammals having a placenta; all mammals except monotremes and marsupials
arboreal nocturnal mammal of southeast Asia and the Philippines resembling a lemur and having a fold of skin on each side from neck to tail that is used for long gliding leaps