The Collaborative International Dictionary
monocarbonic
monocarbonic \mon`o*car*bon"ic\, monocarboxylic \mon`o*car*box*yl"ic\, a. [Mono- + carbonic.] (Chem.) Containing one carboxyl group; as, acetic acid is a monocarbonic acid. The more common term is monocarboxylic. Contrasted with dicarboxylic, tricarboxylic, etc.
Wiktionary
monocarbonic
a. (context chemistry English) Containing a single carboxyl group.