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The Collaborative International Dictionary
phthalic

Naphthalic \Naph*tha"lic\, a. (Chem.)

  1. Pertaining to, derived from, or related to, naphthalene; -- formerly used to denote any one of a series of acids derived from naphthalene, and called naphthalene acids, now specifically referring to 1,8-naphthalenedicaboxylic acid, C12H8O4.

  2. Formerly, designating an acid probably identical with phthalic acid.

Wiktionary
phthalic

a. (context chemistry English) of, relating to, or derived from naphthalene or phthalic acid

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