Mare and Foal
A "foal" is a horse that is one year old or younger. More specific terms are "colt" for a male foal and "filly" for a female foal, but these terms are used until the horse is age three or four. When the foal is nursing from its dam (mother), it may also be called a "suckling." After the young horse has been weaned from its dam, it may be called a "weanling." After a horse is one year old, it is called a "yearling."