Quinoline \Quin"o*line\, n. [Quinine + L. oleum oil + -ine.] (Chem.) A nitrogenous base, {C9H7N} obtained as a pungent colorless liquid by the distillation of alkaloids, bones, coal tar, etc. It the nucleus of many organic bodies, especially of certain alkaloids and related substances; hence, by extension, any one of the series of alkaloidal bases of which quinoline proper is the type. [Written also {chinoline}.] [1913 Webster]