What term is used for a young female horse?

The correct term for a young female horse is "filly." A filly is typically defined as a female horse that is under the age of four years. This designation indicates not only her gender but also her age, which is important for various classifications in breeding, showing, and competition. Understanding this term helps in proper communication within the equine industry, especially when discussing the development stages of horses.

In contrast, a colt refers specifically to a young male horse, distinguishing it from the term for females. A mare is a mature female horse, typically over the age of four, which further clarifies the difference in age and maturity between a filly and a mare. The term yearling refers to a horse that is one year old, regardless of gender, which adds another layer to understanding equine classifications but does not specifically indicate a female. Thus, recognizing "filly" as the term for a young female horse is essential for proper terminology in horse evaluation and discussions.