You have probably come across the two terms “grulla” and “grullo,” and wondered what the difference is if there is one. The answer is that there isn’t a definitive difference, although people do use them differently – and some people use them interchangeably. “Grulla” is the Spanish word for “crane,” which shares the gray coloration of the horse. “grullo” means “gray horse,” but because Spanish is a gendered language, many people use “grullo” to refer to geldings and stallions, and “grulla” to refer to fillys and mares. Therefore, a person might refer to a stallion as a grullo, while a mare would be grulla. You can, however, use the terms as you prefer and everybody will understand what you are referring to.