Definition of "phthalic anhydride" [phthalic anhydride]

• A white crystalline compound, C6H4(CO)2O, prepared by oxidizing naphthalene and used in the manufacture of phthaleins and other dyes, resins, plasticizers, and insecticides. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.