Define oxo acid

An oxoacid (or oxyacid) is an acid that contains oxygen, hydrogen, and at least one other element, with the acidic hydrogen atom(s) bonded to an oxygen atom. The central atom is typically bonded to one or more oxygen atoms, and at least one of these oxygen atoms is also bonded to a hydrogen atom. An example is sulfuric acid ($\text{H}_2\text{SO}_4$).