passport

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An official document issued by a government identifying a citizen, certifying his or her nationality, and formally requesting admittance and safe passage from foreign countries.
• noun An official permit issued by a foreign country allowing one to transport goods or to travel through that country.
• noun An official document issued by an allied foreign government to a ship, especially a neutral merchant ship in time of war, authorizing it to enter and travel through certain waters freely.
• noun Something that gives one the right or privilege of passage, entry, or acceptance.

from The Century Dictionary.

• To supply or provide with a passport.
• noun A document issued by competent civil authority, granting permission to the person specified in it to travel, or authenticating his right to protection.
• noun A safe-conduct granted in time of war for persons and effects in a hostile country.
• noun A license for importing or exporting goods subject to duty without paying the usual duties.—4. Anything which enables one to pass with safety or certainty; a certificate; a voucher.
• noun That which enables one to attain any object or reach any end.

from the GNU version of the Collaborative International Dictionary of English.

• noun Permission to pass; a document given by the competent officer of a state, permitting the person therein named to pass or travel from place to place, without molestation, by land or by water.
• noun A document carried by neutral merchant vessels in time of war, to certify their nationality and protect them from belligerents; a sea letter.
• noun A license granted in time of war for the removal of persons and effects from a hostile country; a safe-conduct.
• noun Figuratively: Anything which secures advancement and general acceptance.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An official document normally used for international journeys, which proves the identity and nationality of the person for whom it was issued.
• noun by extension, informal Any document that allows entry or passage.
• noun figuratively Something which enables someone to do or achieve something.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a document issued by a country to a citizen allowing that person to travel abroad and re-enter the home country
• noun any quality or characteristic that gains a person a favorable reception or acceptance or admission
• noun any authorization to pass or go somewhere