\ri-▐dәk-shәn\ n [ME reduccion restoration, fr. MF reduction, fr. LL & L reduction-, reductio reduction (in a syllogism), fr. L, restoration, from reducere] (1546) (1) Any chemical process that increases the proportion of hydrogen or base-forming elements or radicals in a compound. (2) The gaining of electrons by an atom, ion, or element, thereby reducing the positive valence of that which gained the electron(s) (Whitten KW, Davis RE, Davis E, Peck LM, Stanley GG (2003) General chemistry. Brookes/Cole, New York). The reverse of Oxidation.