'Megathere' definitions:

Definition of 'megathere'

From: WordNet
noun
Gigantic extinct terrestrial sloth-like mammal of the Pliocene and Pleistocene in America [syn: ground sloth, megathere]

Definition of 'Megathere'

From: GCIDE
  • Megathere \Meg"a*there\, Megatherium \Meg`a*the"ri*um\, n. [NL. megatherium, fr. Gr. me`gas great + qhri`on beast.] (Paleon.) An extinct gigantic quaternary mammal, allied to the ant-eaters and sloths. Its remains are found in South America. [1913 Webster]