Foal

Definition:

(n.) The young of any animal of the Horse family (Equidae); a colt; a filly.
(v.t.) To bring forth (a colt); -- said of a mare or a she ass.
(v.i.) To bring forth young, as an animal of the horse kind.

Compare foal with other words:

foal vs. yearling

foal vs. suckling

foal vs. offspring

foal vs. stallion