What does "marque" mean?

Marque: A license to pass the limits of a jurisdiction, or boundary of a country, for the purpose of making reprisals. Letters of marque, Letters of marque and reprisal, a license or extraordinary commission granted by a government to a private person to fit out a privateer or armed ship to cruise at sea and make prize of the enemy's ships and merchandise. The ship so commissioned is sometimes called a letter of marque.