Naphthalic \Naph*tha"lic\, a. (Chem.)
(a) 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}.
(b) Formerly, designating an acid probably identical with
{phthalic} acid.
[1913 Webster +PJC]