/ Dictionary / Index P phosphate rock: Meaning and Definition of Find definitions for: phos'phate rock' Pronunciation: [key] phosphorite. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. phosphate group phosphatic Related Content Daily Word Quiz: longevity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language