From WordNet (r) 2.0 (August 2003) [wn]:
jerboa
n : mouselike jumping rodent
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Jerboa \Jer*bo"a\, n. [Ar. yarb[=u]`.] (Zool.)
Any small jumping rodent of the genus Dipus, esp. {Dipus
Aegyptius}, which is common in Egypt and the adjacent
countries. The jerboas have very long hind legs and a long
tail. [Written also gerboa.]
[1913 Webster]
Note: The name is also applied to other small jumping
rodents, as the Pedetes Caffer, of the Cape of Good
Hope.
[1913 Webster]
Jerboa kangaroo (Zool.), small Australian kangaroo
(Bettongia penicillata), about the size of a common
hare.
[1913 Webster]