pyridine

A flammable, colorless or yellowish liquid base, C₅H₅N, having a penetrating odor and serving as the parent compound of many biologically important derivatives. It is used as a solvent and waterproofing agent and in the manufacture of various drugs and vitamins.

A colorless liquid (C₅H₅N) of pungent odor, derived from coal-tar, and useful in allaying asthmatic paroxysms.

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 ptomaïnes, may be mentioned. See lutidine.

Any of a class of aromatic heterocyclic compounds containing a ring of five carbon atoms and an nitrogen atom; especially the simplest one, C5H5N.

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