Thoroughbred

Bred from the best blood through a long line; pure-blooded; -- said of stock, as horses. Hence, having the characteristics of such breeding; mettlesome; courageous; of elegant form, or the like.

A thoroughbred animal, especially a horse.

a pedigreed animal of unmixed lineage; used especially of horses

a racehorse belonging to a breed that originated from a cross between Arabian stallions and English mares