1) Chemical nomenclature 2) Monotypic 
• (a.) Capable of being neutralized by a univalent base or basic radical; having but one acid hydrogen atom to be replaced; -- said of acids; as, acetic, nitric, and hydrochloric acids are monobasic.
(mon″o-ba´sik) having but one atom of replaceable hydrogen.
Mon`o·ba'sic adjective [ Mono- + basic .] (Chemistry) Capable of being neutralized by a univalent base or basic radical; having but one acid hydrogen atom to be replaced; -- said of acids; as, acetic, nitric, and hydrochloric acids are monobasic . 
Type: Term Pronunciation: mon′ō-bā′sik Definitions: 1. Denoting an acid with only one replaceable hydrogen atom, or only one replaced hydrogen atom.
(of an acid) containing one replaceable hydrogen atom. · monotypic.