megatherium

from WordNet (r) 3.0 (2006)

Megatherium
    n 1: type genus of the Megatheriidae [syn: {Megatherium}, {genus
         Megatherium}]

from The Collaborative International Dictionary of English v.0.48

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]