Phthalide
Pronunciation : Phthal"ide
Part of Speech : n.
Etymology : [Phthalyl + anhydride.] (Chem.)
Definition : Defn: A lactone obtained by reduction of phthalyl chloride, as a white crystalline substance; hence, by extension, any one of the series of which phthalide proper is the type. [Written also phthalid.]
Source : Webster's Unabridged Dictionary, 1913