n. The act of reducing, or the state of being reduced.n. Conversion into another state or form: as, the reduction of a body to powder; the reduction of things to order.n. (c.) Diminution: as, the reduction of the expenses of government; the reduction of the national debt; a reduction of 25 per cent. made to wholesale buyers.n. Conquest; subjugation: as, the reduction of a province under the power of a foreign nation; the reduction of a fortress.n. A settlement or parish of South American Indians converted and trained by the Jesuits.n. The bringing of a problem to depend on a problem already solved.n. The transformation of an algebraic expression into another of a simpler kind.n. The lowering of the values of the numerator and denominator of a fraction, or of the antecedent and consequent of a ratio, by dividing both by the same quantity.n. The conversion of a quantity expressed in terms of one denomination so as to express it in terms of another denomination. Ascending reduction is conversion to terms of larger units; descending reduction, conversion to terms of smaller units.n. The proof of the conclusion of an indirect syllogism from its premises by means of a direct syllogism and immediate inferences. This is said to be a reduction to the mode of direct syllogism employed.n. A direct syllogism proving, by means of conversions and other immediate inferences, that the conclusion of an indirect syllogism follows from its premises.n. The act or process of making a copy of a figure, map, design, draft, etc., on a smaller scale, preserving the original proportions; also, the result of this process.n. In surg, the operation of restoring a dislocated or fractured bone to its former place.n. Separation of a metal from substances combined with it: used especially with reference to lead, zinc, and copper, and also applied to the treatment of iron ore, as when steel is made from it by a direct process.n. In astronomy, the correction of observed quantities for instrumental errors, as well as for refraction, parallax, aberration, precession, and nutation, so as to bring out their cosmical significance. A similar process is applied to observations in other physical sciences.n. In Scots law, an action for setting aside a deed, writing, etc.n. Synonyms Lessening decrease, abatement, curtailment, abridgment, contraction. retrenchment.n. In linguistics, the shortening of a word by apocope.n. In cytology, the halving of the number of somatic chromosomes during spermatogenesis and oögenesis.