/ Dictionary / Index P phosphatase: Meaning and Definition of Find definitions for: phos•pha•tase Pronunciation: (fos'fu-tās", -tāz"), [key] — n. Biochem. any of several classes of esterases of varying specificity that catalyze the hydrolysis of phosphoric esters. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phosphatase (Thesaurus) phosphamidon phosphate Related Content Daily Word Quiz: dissonant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language