Source : Webster's Revised Unabridged Dictionary (1913)

Pyrogallic \Pyr`o*gal"lic\, a. [Pyro- + gallic.] (Chem.)
   Pertaining to, derived from, or designating, an acid called
   pyrogallol. See {Pyrogallol}.

Source : WordNet®

pyrogallic
     adj : of or relating to pyrogallol