Q-ship
/ˈkjuːˈʃɪp/noun
- historical a merchant ship with concealed weapons, used by the British in the First and Second World Wars in an attempt to destroy submarines〈史〉神秘船（第一、第二次世界大战中英国试图用以击毁潜艇的带有隐蔽武器的商船）。
词源
First World War: from Q as a non-explicit symbol of the type of vessel+SHIP.