A guaranty or security granted by the king under the great seal to a stranger, for his safe coming into and passing out of the kingdom. Cowell. One of the papers usually carried by vessels in time of war, and necessary to the safety of neutral merchantmen. It is in the nature of a license to the vessel to proceed on a designated voyage, and commonly contains the name of the master, the name, description , and nationality of the ship, the voyage intended, and other matters.