Oxoacids (and its variants oxyacids, oxo acids, oxy-acids, oxiacids, oxacids) is a traditional name for any acid having oxygen in the acidic group. The term stands in contradistinction to `hydracids' (e.g. $\ce{HCl}$) lacking oxygen. The term oxoacid now refers to a compound which contains oxygen, at least one other element, and at least one hydrogen bound to oxygen, and which produces a conjugate base by loss of positive hydrogen ion(s) (hydrons). E.g. $\ce{P(OH)3}$, $\ce{RC(=O)OH}$, $\ce{HOSOH}$, $\ce{HOCl}$, $\ce{HON=O}$, $\ce{(HO)2SO2}$, $\ce{RP(=O)(OH)2}$.