megathere vs ground sloth

megathere and ground sloth both are nouns.

Word	Noun	Adjective	Verb	Adverb
megathere	Yes	No	No	No
ground sloth	Yes	No	No	No

As nouns, megathere and ground sloth are synonyms defined as:

megathere and ground sloth: gigantic extinct terrestrial sloth-like mammal of the Pliocene and Pleistocene in America

megathere (noun)	ground sloth (noun)
gigantic extinct terrestrial sloth-like mammal of the Pliocene and Pleistocene in America	gigantic extinct terrestrial sloth-like mammal of the Pliocene and Pleistocene in America