service-cap
Serv"ice cap or hat. (Mil.) Defn: A cap or hat worn by officers or enlisted men when full-dress uniform, or dress uniform, is not worn. In the United States army the service cap is round, about 3½ inches high, flat-topped, with a visor. The service hat is of soft felt of khaki color, with broad brim and high crown, creased down the middle.