Definify.com
Webster 1913 Edition
Euchroic
Eu-chro′ic
,Adj.
 [Gr. [GREEK] well-colored; 
εὖ 
well + [GREEK] color.] (Chem.) 
Having a fine color. 
Euchroic acid 
(Chem.)
, an organic, imide acid, obtained as a colorless crystalline substance, 
 C12H4N2O8 
by heating an ammonium salt of mellitic acid. By reduction it is changed to a dark blue substance (euchrone), – hence its name.