Source : Webster's Revised Unabridged Dictionary (1913)

Rheic \Rhe"ic\, a. [NL. Rheum rhubarb, Gr. ??? See {Rhubarb}.]
   (Chem.)
   Pertaining to, or designating, an acid (commonly called
   chrysophanic acid) found in rhubarb ({Rheum}). [Obsoles.]