1. 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.
2. An official permit issued by a foreign country allowing one to transport goods or to travel through that country.
3. 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.
4. Something that gives one the right or privilege of passage, entry, or acceptance: Hard work was her passport to success.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.