Oxidation, in common parlance, is the process or product of a substance combining with oxygen. The oxidation process may be slow as when a hammer left outside overnight rusts (iron changing to iron oxide). A faster example of oxidation is when a cut apple or banana turns brown.
Not all oxidation is negative. Oxidation is essential to the body’s metabolism of food for energy. Wine begins oxidizing as soon as the bottle is open and allowed to “breathe” which enhances the flavor. Open to air too long, however, the wine more fully oxidizes, and wine-lovers consider the flavor “off”. Rapid oxidation occurs when wood or a hydrocarbon burns. In chemistry, the more technical definition of oxidation is the loss of at least one electron in the interaction of two or more substances, not necessarily involving oxygen.