a chemical reaction in which one of the reactants is reduced (gains one or more electrons) and another reactant is oxidized (loses one or more electrons)
See oxidation-reduction in American Heritage Dictionary 4
(ŏkˌsĭ-dāˈshən-rĭ-dŭkˈshən)
noun
A chemical reaction in which an atom or ion loses electrons to another atom or ion.