/ Dictionary / Index P phthalic anhydride: Meaning and Definition of Find definitions for: phthal'ic anhy'dride Pronunciation: [key] — Chem. Chem. a white, crystalline, slightly water-soluble solid, CHO, used chiefly in the manufacture of dyes, alkyd resins, and plasticizers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. phthalic acid phthalin Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language