Source : Webster's Revised Unabridged Dictionary (1913)

Terephthalic \Ter`eph*thal"ic\, a. [Terebene + phthalic.]
   (Chem.)
   Of, pertaining to, or designating, a dibasic acid of the
   aromatic series, metameric with phthalic acid, and obtained,
   as a tasteless white crystalline powder, by the oxidation of
   oil of turpentine; -- called also {paraphthalic acid}. Cf.
   {Phthalic}.