Source : Webster's Revised Unabridged Dictionary (1913)

Bilirubin \Bil`i*ru"bin\, n. [L. bilis biel + ruber red.]
   (Physiol.)
   A reddish yellow pigment present in human bile, and in that
   from carnivorous and herbivorous animals; the normal biliary
   pigment.

Source : WordNet®

bilirubin
     n : 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: {hematoidin},
          {haematoidin}]