/ Dictionary / Index P powder horn: Meaning and Definition of Find definitions for: pow'der horn" Pronunciation: [key] a powder flask made from the horn of a cow or ox. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. powder flask powder keg Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language