From The Collaborative International Dictionary of English v.0.48 :
Sciurus \Sci*u"rus\, n. [L., a squirrel, Gr. ?. See Squirrel.]
(Zool.)
A genus of rodents comprising the common squirrels.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
Sciurus
n 1: type genus of the Sciuridae; typical moderate-sized
arboreal squirrels [syn: Sciurus, genus Sciurus]