'Service cap' definitions:

Definition of 'service cap'

(from WordNet)
noun
A cap with a flat circular top and a visor [syn: kepi, peaked cap, service cap, yachting cap]

Definition of 'Service cap'

From: GCIDE
  • Service cap \Serv"ice cap\ or Service hat \Serv"ice hat\ (Mil.) A cap or hat worn by officers or enlisted men when full-dress uniform, or dress uniform, is not worn.
  • Note: In the United States army the service cap is round, about 31/2 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. [Webster 1913 Suppl.]