what is a colt horse

A colt is a male horse, pony, donkey, or mule younger than four years of age. The term "colt" only describes young male horses and is not to be confused with "foal," which is a horse of either sex less than one year of age. Similarly, a yearling is a horse of either sex between the ages of one and two. A young female horse is called a filly, and a mare once she is an adult animal. In horse racing, particularly for Thoroughbreds in the United Kingdom, a colt is defined as an uncastrated male from the age of two up to and including the age of four. An adult male horse, if left intact, is called either a "stallion" if used for breeding, or a horse (sometimes full horse); if castrated, it is called a gelding. In some cases, particularly informal nomenclature, a gelding under four years is still called a colt.