Pyridine

A nitrogenous base, C5H5N, obtained from the distillation of bone oil or coal tar, and by the decomposition of certain alkaloids, as a colorless liquid with a peculiar pungent odor. It is the nucleus of a large number of organic substances, among which several vegetable alkaloids, as nicotine and certain of the ptomaines, may be mentioned. See Lutidine.

a toxic colorless flammable liquid organic base with a disagreeable odor; usually derived from coal