The Collaborative International Dictionary
Megatheroid
Megatheroid \Meg`a*the"roid\, n. [Megatherium + -oid.] (Paleon.) One of a family of extinct edentates found in America. The family includes the megatherium, the megalonyx, etc.
Wiktionary
megatheroid
n. (context paleontology English) One of a family of extinct edentates found in America, including the megatherium and the megalonyx, among others.