The Collaborative International Dictionary of English v.0.48:

Chrysarobin \Chrys`a*ro"bin\, n. [Gr. chryso`s gold + araroba a
   foreign name of Goa powder + -in.] (Chem.)
   A bitter, yellow substance forming the essential constituent
   of Goa powder, and yielding chrysophanic acid proper; hence
   formerly called also chrysphanic acid.
   [1913 Webster]

WordNet (r) 3.0 (2006):

chrysarobin
    n 1: a bitter yellow powder used to treat skin diseases [syn:
         araroba, Goa powder, chrysarobin]