The adjective that describes a black and white horse is "pinto." Pinto is a term used to describe a horse with a coat pattern characterized by large patches of contrasting colors, typically black and white. The patches can be irregular in shape and distribution, creating a striking and distinctive appearance. Pinto horses are often referred to as "piebald" or "skewbald" based on the specific color patterns they exhibit. The term "pinto" can also be used to describe horses with other combinations of colors, such as brown and white or chestnut and white.