/ Dictionary / Index P postbox: Meaning and Definition of Find definitions for: post•box Pronunciation: (pōst'boks"), [key] — n. Chiefly Brit. a mailbox, esp. one for public deposit of mail. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: postbox (Thesaurus) post-boat postboy Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language