aldehyde /al″dəhīd′/ [Ar, alkohl + L, dehydrogenatum, dehydrogenated] , any of a large category of organic compounds derived from the oxidation of a corresponding primary alcohol, as in the conversion of ethyl alcohol to acetaldehyde, also known as ethanal. Each aldehyde is characterized by a carbonyl group (‒CO‒) attached directly to a hydrogen (‒CHO) in its formula and can be converted into a corresponding acid by oxidation, as in the conversion of acetaldehyde to acetic acid.
