Which term describes a white marking that resembles a flash or spot on a horse's face?

The term that accurately describes a white marking on a horse's face resembling a flash or spot is "Bald Face." A bald face generally extends across the forehead and can cover a significant portion of the face, often reaching the eyes and nostrils. This feature is prominent and recognizable, which makes the term distinct from others.

In contrast, "snip" refers to a smaller, usually white mark located on the nose or muzzle, while "star" denotes a small white spot located specifically on the forehead. On the other hand, "blaze" describes a wider stripe of white that runs down the center of the face but is not as extensive as a bald face. The key distinction of a bald face lies in its broad coverage, highlighting its defining characteristics.