Phthal"ide (?), n. [Phthalyl + anhydride.] Chem.
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.]
<-- phthalic anhydride? would be classed as an acid anhydride, rather than a lactone. Obtained commercially by a different process. -->
© Webster 1913.