-CN

Nitrile Ni"trile (? or ?), n. [See {Nitro-}.] (Chem.) Any one of a series of compounds bearing the cyanide radical ({-CN}); particularly, one of those cyanides of alcohol radicals which, by boiling with acids or alkalies, produce a carboxyl acid, with the elimination of the nitrogen as ammonia. [1913 Webster]

Note: The nitriles are named with reference to the acids produced by their decomposition, thus, hydrocyanic acid is {formic nitrile}, methyl cyanide is {acetonitrile} (also {acetic nitrile}), and ethyl cyanide is {propionitrile} (from propionic acid). [1913 Webster +PJC]