/ Dictionary / Index P postal code: Meaning and Definition of Find definitions for: post'al code" Pronunciation: [key] postcode. a mailing code system similar to the zip code in the U.S. and the postcode in Britain. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. postal carrier postal delivery zone Related Content Daily Word Quiz: cosmology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language