the yellowish-red chief pigment, CHNO, of human bile, derived from biliverdin and found in small quantities in blood and urine: high concentrations change the color of blood and urine and result in jaundice
See bilirubin in American Heritage Dictionary 4
(bĭlˌĭ-ro͞oˈbĭn, bĭlˈĭ-ro͞oˌ-)
noun
A reddish-yellow bile pigment, C33H36N4O6, derived from the degradation of heme.