A document that indicates permission granted by a sovereign to its citizen to travel to foreign countries and return and requests foreign governments to allow that citizen to pass freely and safely.
With respect to INTERNATIONAL LAW, a passport is a license of safe conduct, issued during a war, that authorizes an individual to leave a war-ring nation or to remove his or her effects from that nation to another country; it also authorizes a person to travel from country to country without being subject to arrest or detention because of the war.
In maritime law, a passport is a document issued to a neutral vessel by its own government during a war that is carried on the voyage as evidence of the nationality of the vessel and as protection against the vessels of the warring nations. This paper is also labeled a pass, sea-pass, sealetter, or sea-brief. It usually contains the captain's or master's name and residence; the name, property, description, tonnage, and destination of the ship; the nature and quantity of the cargo; and the government under which it sails.