Of pure or unmixed breed, stock, or race; bred from a sire and dam of the purest or best blood. See II.Hence Having the qualities characteristic of pure breeding; high-spirited; mettlesome; elegant or graceful in form or bearing: sometimes applied colloquially to persons.Thoroughgoing; thorough.n. An animal, especially a horse, of pure blood, stock, or race; strictly, and as noting horses, a race-horse all of whose ancestors for a given number of generations (seven in England, five in America) are recorded in the stud-book.