reduction /riduk″shən/ [L, reducere] , 1. the addition of hydrogen to a substance. Also called hydrogenation. 2. the removal of oxygen from a substance. 3. the decrease in the valence of the electronegative part of a compound. 4. the addition of one or more electrons to a chemical substance. 5. the correction of a fracture, hernia, or luxation. 6. the reduction of data, as in converting interval data to an ordinal or nominal scale of measurement.
