any member of three breeds of sturdily built dog with a wiry, pepper-and-salt or black coat, whiskers, and bushy eyebrows, orig. bred in Germany: the standard schnauzer is 17 to 23 in (43.2-58 cm) high at the shoulder; the miniature schnauzer, 12 to 14 in (30.5-35.5 cm); the giant schnauzer, over 23.5 in (59.7 cm)