/ Dictionary / Index P Prussian blue: Meaning and Definition of Find definitions for: Prus'sian blue' Pronunciation: [key] a moderate to deep greenish blue. one of the iron blues, a dark-blue, crystalline, water-insoluble pigment, Fe[Fe(CN)], produced by reacting ferrocyanic acid or a ferrocyanide with a ferric compound: used in painting, fabric printing, and laundry bluing. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Prussian Prussianism Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language