A young horse that is at least one year but less than two years old is known as what?

A young horse that is at least one year but less than two years old is referred to as a yearling. This term is specifically used to describe horses within this age range. Yearlings are at a developmental stage where they are transitioning from foals—who are younger than one year—to older horses.

In this context, a foal is typically defined as a young horse that is less than one year old. A weanling is a foal that has been weaned from its mother, usually between four to six months of age. A stallion, on the other hand, refers to a mature male horse that has reached sexual maturity and is typically at least two years old. Thus, the definition of a yearling aligns perfectly with the question regarding the age of the horse.