What is the term for a bay or brown horse with a lighter colored muzzle?

The term that describes a bay or brown horse with a lighter colored muzzle is known as "mealy mouth." This term refers specifically to the paler coloration found on the muzzle, and it is often associated with certain coat colors, such as bay or brown. The mealy coloration is a result of the horse's genetics and is characteristic of certain breeds or individual horses.

Other terms mentioned in the choices refer to different markings or features. For instance, "blaze" refers to a wide white stripe down the front of a horse's face, "snip" describes a small white marking on the muzzle that is not as extensive as a blaze, and "star" refers to a small white mark on the forehead. These terms do not apply to the specific characteristic of having a lighter colored muzzle on a bay or brown horse, which is why mealy mouth is the correct answer.