from
The Collaborative International Dictionary of English v.0.48
Koulan \Kou"lan\, n. [Native name.] (Zool.)
A wild horse ({Equus onager} or {Asinus onager}) inhabiting
the plains of Central Asia; -- called also {gour}, {khur},
and {onager}. [Written also {kulan}.]
[1913 Webster]
Note: It is sometimes confounded with the dziggetai, to which
it is closely related. It is gray in winter, but
fulvous in summer. It has a well defined, dark, dorsal
stripe, and a short, erect mane. In size, it is
intermediate between the horse and ass.
[1913 Webster]