\Styph"nic\, a. [Gr. (spurious) sty`fein to contract.]
(Chem.)
Pertaining to, or designating, a yellow crystalline
astringent acid, {(NO2)3.C6H.(OH)2}, obtained by the action
of nitric acid on resorcin. Styphnic acid resembles picric
acid, but is not bitter. It acts like a strong dibasic acid,
having a series of well defined salts.