- an acid containing a larger proportion of oxygen than other acids containing the same elements, as perboric acid or perchloric acid
- an acid that contains one or more O groups
Origin of peracidtranslated, translation of German persäure: see per- and acid
- Any of various acids containing the peroxy group.
- An inorganic acid, such as perchloric acid, containing the largest proportion of oxygen in a series of related oxyacids.