hippo vs hippopotamus

hippo and hippopotamus both are nouns.

Word	Noun	Adjective	Verb	Adverb
hippo	Yes	No	No	No
hippopotamus	Yes	No	No	No

As nouns, hippo and hippopotamus are synonyms defined as:

hippo and hippopotamus: massive thick-skinned herbivorous animal living in or around rivers of tropical Africa

Other synonyms of hippo include Hippopotamus amphibius, river horse.

hippo (noun)	hippopotamus (noun)
massive thick-skinned herbivorous animal living in or around rivers of tropical Africa	massive thick-skinned herbivorous animal living in or around rivers of tropical Africa