Serolin \Ser"o*lin\, n. [Serum + L. oleum oil.] (Physiol. Chem.) (a) A peculiar fatty substance found in the blood, probably a mixture of fats, cholesterin, etc. (b) A body found in fecal matter and thought to be formed in the intestines from the cholesterin of the bile; -- called also {stercorin}, and {stercolin}.