privateer
n//ˌpɹaɪ.vəˈtɪə//kapare, kaparskepp, fribytare
(historical) A privately owned warship that acted under a letter of marque to attack enemy merchant ships and take possession of their cargo. [from 17th c.]
(historical) An officer or any other member of the crew of such a ship; a government-sanctioned pirate. [from 17th c.]