Terms Applied to Horses and Ponies

1. Foal - from birth up to first day of January following birth

2. Colt - a young male up to three years (at birth, colt foal) 

3. Filly - a young female up to three years (at birth, filly foal) 

4. Yearling - in the year after birth

5. Two-year-old - in second year after birth

6. Gelding - a castrated male (any age) 

7. Entire/stallion - an uncastrated male of over three years

8. Mare - a female over three years of age