The Collaborative International Dictionary of English v.0.48:

Hematoidin \Hem`a*toid"in\, n. (Physiol. Chem.)
   A crystalline or amorphous pigment, free from iron, formed
   from hematin in old blood stains, and in old hemorrhages in
   the body. It resembles bilirubin. When present in the corpora
   lutea it is called h[ae]molutein.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hematoidin
    n 1: an orange-yellow pigment in the bile that forms as a
         product of hemoglobin; excess amounts in the blood produce
         the yellow appearance observed in jaundice [syn:
         bilirubin, hematoidin, haematoidin]