What is a castrated male horse called?

A castrated male horse is called a gelding. This term specifically refers to a male horse that has undergone castration, which is the surgical removal of the testicles. The process of gelding is done for various reasons, including making the horse easier to handle, particularly in training and competition settings, as it often results in a calmer animal.

When discussing other terms: a pony refers to a small horse, typically measuring less than 14.2 hands at the withers, and has no relation to whether it is castrated or not. A colt is a young male horse that has not been castrated, usually under the age of two. A stallion is an intact male horse that has not been castrated and is often used for breeding purposes. Therefore, only the term for a castrated male horse in this context is gelding.