Definition of Q-ship in English:

noun

• A merchant ship with concealed weapons, used by the British in World War I and World War II in an attempt to destroy submarines.

  ‘U-boats were attacked by aircraft, airships, Q-ships, mines, drifters, Naval vessels (including submarines) and merchant ships.’

  ‘The Eastern Sea Frontier, which operated the few Q-ships the US Navy used during the war, was the parent organization.’