/ Dictionary / Index P post horn: Meaning and Definition of Find definitions for: post' horn" Pronunciation: [key] — n. a straight or coiled copper or brass horn with no valves or slide, originally used to announce mail coaches. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. posthole digger post horse Related Content Daily Word Quiz: designate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language