/ Dictionary / Index T terephthalic acid: Meaning and Definition of Find definitions for: ter'eph•thal'ic ac'id Pronunciation: (ter'ef-thal'ik, ter"-), [key] — Chem. Chem. a white, crystalline, water-insoluble solid, CHO, the para isomer of phthalic acid: used chiefly in the manufacture of resins and textile fibers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. terephthalate Teresa Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language