hippo vs artiodactyl mammal

hippo and artiodactyl mammal both are nouns.

Word	Noun	Adjective	Verb	Adverb
hippo	Yes	No	No	No
artiodactyl mammal	Yes	No	No	No

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

hippo: massive thick-skinned herbivorous animal living in or around rivers of tropical Africa
artiodactyl mammal: placental mammal having hooves with an even number of functional toes on each foot

Other hypernyms of hippo include artiodactyl, even-toed ungulate.

hippo (noun)	artiodactyl mammal (noun)
massive thick-skinned herbivorous animal living in or around rivers of tropical Africa	placental mammal having hooves with an even number of functional toes on each foot