thor·ough·bred 
(thûrō-brĕd′, thûrə-, thŭr-)
(thûrō-brĕd′, thûrə-, thŭr-)n.
1. A purebred or pedigreed animal, especially a horse.
2. Thoroughbred Any of a breed of horses, bred chiefly for racing, originating from crosses between Arabian stallions and English mares.
3. A well-bred person.
adj.
1. Bred of pure stock; purebred.
2. Thoroughbred Relating or belonging to horses of the Thoroughbred.
3. Thoroughly trained or educated; well-bred.