Source : Webster's Revised Unabridged Dictionary (1913)

Xanthic \Xan"thic\, a. [Gr. xanqo`s yellow: cf. F. xanthique.]
   1. Tending toward a yellow color, or to one of those colors,
      green being excepted, in which yellow is a constituent, as
      scarlet, orange, etc.

   2. (Chem.)
      (a) Possessing, imparting, or producing a yellow color;
          as, xanthic acid.
      (b) Of or pertaining to xanthic acid, or its compounds;
          xanthogenic.
      (c) Of or pertaining to xanthin.

   {Xanthic acid} (Chem.), a heavy, astringent, colorless oil,
      {C2H5O.CS.SH}, having a pungent odor. It is produced by
      leading carbon disulphide into a hot alcoholic solution of
      potassium hydroxide. So called from the yellow color of
      many of its salts. Called also {xanthogenic acid}.

   {Xanthic colors} (Bot.), those colors (of flowers) having
      some tinge of yellow; -- opposed to {cyanic colors}. See
      under {Cyanic}.

Source : WordNet®

xanthic acid
     n : any of a class of unstable organic acids containing sulphur