chipmunk

from WordNet (r) 3.0 (2006)

chipmunk
    n 1: a burrowing ground squirrel of western America and Asia;
         has cheek pouches and a light and dark stripe running down
         the body

from The Collaborative International Dictionary of English v.0.48

Chipmunk \Chip"munk`\, n. [Indian name.] (Zool.)
   A squirrel-like animal of the genus {Tamias}, sometimes
   called the {striped squirrel}, {chipping squirrel}, {ground
   squirrel}, {hackee}. The common species of the United States
   is the {Tamias striatus}. [Written also {chipmonk},
   {chipmuck}, and {chipmuk}.]
   [1913 Webster]