noun
colt
KOHLT/kəʊlt/
A young male horse.
The colt stands in the pasture on long, slender legs.

Etymology
Old English colt named a young horse and could also refer to other young animals. The usual modern application is specifically male, with filly naming the young female horse.
In context
As regards that young horse,” said Mahbub, “I say that when a colt is born to be a polo-pony
More examples
- The mare watches her colt explore the field.
- Two colts trot along the fence together.
- She gently introduces the colt to a halter.