Quinaldine \Quin*al"dine\, n. [Quinoline + aldehyde + aniline.] (Chem.) A colorless liquid of a slightly pungent odor, {C9H6N.CH3}, first obtained as a condensation product of aldehyde and aniline, and regarded as a derivative of quinoline; -- called also {methyl quinoline}. [Written also {chinaldine}.]