Source : Webster's Revised Unabridged Dictionary (1913)

Pyrrol \Pyr"rol\, n. [Gr. ? flame-colored (from ? fire) + L.
   oleum oil.] (Chem.)
   A nitrogenous base found in coal tar, bone oil, and other
   distillates of organic substances, and also produced
   synthetically as a colorless liquid, {C4H5N}, having on odor
   like that of chloroform. It is the nucleus and origin of a
   large number of derivatives. So called because it colors a
   splinter of wood moistened with hydrochloric acid a deep red.