Which term signifies a mature female horse?

A mature female horse is specifically referred to as a mare. This term distinguishes adult female horses from younger females, which are called fillies until they reach maturity. Understanding horse classifications is essential in equine studies, as they indicate the animal's age and reproductive status.

In contrast, a stallion refers to a mature male horse, while a pony is a different category that emphasizes size rather than age or sex, typically describing smaller horse breeds. This highlights the importance of terminology in animal science, as using the correct terms allows for clear communication about an animal's characteristics.