alcohols substituted by a cyano group, most commonly, but not limited to, examples having a cyano and a hydroxy group attached to the same carbon atom, formally derived from aldehydes or ketones by the addition of hydrogen cyanide. An individual cyanohydrin can systematically be named as a hydroxy nitrile, e.g. (CH₃)₂C(OH)C≡N 'acetone cyanohydrin' (2-hydroxy-2-methylpropanenitrile), HOCH₂CH₂C≡N 'ethylene cyanohydrin' (3-hydroxypropanenitrile).