The Collaborative International Dictionary of English v.0.48:

Tamias \Ta"mi*as\, n. [NL., fr. Gr. ? a distributer.] (Zool.)
   A genus of ground squirrels, including the chipmunk.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Tamias
    n 1: chipmunks of eastern North America [syn: Tamias, genus
         Tamias]