After a horse is one year old, it is no longer a foal, and is a "yearling". There are no special age-related terms for young horses older than yearlings. When young horses reach breeding maturity, the terms change: a filly over three (four in horse racing) is called a mare, and a colt over three is called a stallion. A castrated male horse is called a gelding regardless of age; however, colloquially, the term "gelding colt" is sometimes used until a young gelding is three or four. (There is no specific term for a spayed mare other than a "spayed mare".)