/ Dictionary / Index P prayer book: Meaning and Definition of Find definitions for: prayer' book" Pronunciation: (prâr), [key] a book containing formal prayers to be used in public or private religious devotions. (usually caps.) See a small holystone. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: prayerbook (Thesaurus) prayer beads prayer flag Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language