Nitrile \Ni"trile\ (? or ?), n. [See Nitro-.]

(Chem.) Any one of a series of cyanogen compounds; 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.

Note: The nitriles are named with reference to the acids produced by their decomposition, thus, hydrocyanic acid is formic nitrile, and methyl cyanide is acetic nitrile.

Source: Webster's Revised Unabridged Dictionary (1913)