What is the term for a castrated male horse?

The term for a castrated male horse is a gelding. Castration removes the testicles, greatly reducing testosterone and usually making the horse calmer and easier to manage than an intact male.

Geldings have been used for centuries in riding, farming, transport, and military work. Because they cannot reproduce, breeders can select them primarily for temperament, training, athletic ability, or usefulness. Castration is commonly performed when a male horse is young, though timing depends on veterinary advice and the animal’s intended use.

A gelding is not the same as a stallion, which is an adult uncastrated male horse. A mare is an adult female, while a foal is a young horse of either sex. The word “gelding” describes sex and reproductive status, not a particular breed, age, color, or size. Many famous sport and working horses have been geldings, including elite racehorses, show jumpers, and riding horses.