1. A window in a ship or aeroplane
   "Passengers peered out of the portholes as the ship entered the harbour"
    
2. An opening (in a wall, ship or armoured vehicle) for firing through
   "The castle's portholes allowed archers to shoot while remaining protected";
   - port, embrasure

Derived forms: portholes

Type of: opening, window

Part of: fuselage, ship

Encyclopedia: Porthole