REDU'CE, v.t. [L. reduco; re and duco, to lead or bring.]

1. Literally, to bring back; as, to reduce these bloody days again. – Shak. [In this sense, not in use.]
2. To bring to a former state. It were but just / And equal to reduce me to my dust. – Milton.
3. To bring to any state or condition, good or bad; as, to reduce civil or ecclesiastical affairs to order; to reduce a man to poverty; to reduce a state to distress; to reduce a substance to powder; to reduce a sum to fractions; to reduce one to despair.
4. To diminish in length, breadth, thickness, size, quantity or value; as, to reduce expenses; to reduce the quantity any thing; to reduce the intensity of heat; to reduce this brightness of color or light; to reduce a sum or amount; to reduce the price of goods; to reduce the strength of spirit.
5. To lower; to degrade; to impair in dignity or excellence. Nothing so excellent but a man may fasten on something belonging to it, to reduce it. – Tillotson.
6. To subdue; to bring into subjection. The Romans reduced Spain, Gaul and Britain by their arms.
7. To reclaim to order. – Milton.
8. To bring, as into a class, order, genus or species; to bring under rules or within certain limits of description; as, to reduce animals or vegetables to a class or classes; to reduce men to tribes; to reduce language to rules.
9. In arithmetic, to change numbers from one denominator into another without altering their value; or to change numbers of one denomination into others of the same value; as to reduce a dollar to a hundred cents, or a hundred cents to a dollar.
10. In algebra, to reduce equations, is to clear them of all superfluous quantities, bring them to their lowest terms, am separate the known from the unknown, till at length the unknown quantity only is found on one side and the known ones on the other. – Encyc.
11. In metallurgy, to bring back metallic substances which have been combined, into their original state of metals. – Encyc.
12. In surgery, to restore to its proper place or state a dislocated or fractured bone. To reduce a figure, design or draught, to make a copy of it smaller than the original, but preserving the form and proportion. – Encyc.

1. To bring or lead back to any former place or condition.
   
   
   [Obs.]

   And to his brother's house reduced his wife. Chapman.

   The sheep must of necessity be scattered, unless the great Shephered of souls oppose, or some of his delegates reduce and direct us. Evelyn.

2. To bring to any inferior state, with respect to rank, size, quantity, quality, value, etc.; to diminish; to lower; to degrade; to impair; as, to reduce a sergeant to the ranks; to reduce a drawing; to reduce expenses; to reduce the intensity of heat.
   
   
   "An ancient but reduced family." Sir W. Scott.

   Nothing so excellent but a man may fasten upon something belonging to it, to reduce it. Tillotson.

   Having reduced
   Their foe to misery beneath their fears. Milton.

   Hester Prynne was shocked at the condition to which she found the clergyman reduced. Hawthorne.

3. To bring to terms; to humble; to conquer; to subdue; to capture; as, to reduce a province or a fort.
   
   

4. To bring to a certain state or condition by grinding, pounding, kneading, rubbing, etc.; as, to reduce a substance to powder, or to a pasty mass; to reduce fruit, wood, or paper rags, to pulp.
   
   

   It were but right
   And equal to reduce me to my dust. Milton.

5. To bring into a certain order, arrangement, classification, etc.; to bring under rules or within certain limits of descriptions and terms adapted to use in computation; as, to reduce animals or vegetables to a class or classes; to reduce a series of observations in astronomy; to reduce language to rules.
6. To change, as numbers, from one denomination into another without altering their value, or from one denomination into others of the same value; as, to reduce pounds, shillings, and pence to pence, or to reduce pence to pounds; to reduce days and hours to minutes, or minutes to days and hours.
   
   
   (b)
7. To bring to the metallic state by separating from impurities; hence, in general, to remove oxygen from; to deoxidize; to combine with, or to subject to the action of, hydrogen; as, ferric iron is reduced to ferrous iron; or metals are reduced from their ores; -- opposed to oxidize.
8. To restore to its proper place or condition, as a displaced organ or part; as, to reduce a dislocation, a fracture, or a hernia.
   
   

   Reduced iron (Chem.), metallic iron obtained through deoxidation of an oxide of iron by exposure to a current of hydrogen or other reducing agent. When hydrogen is used the product is called also iron by hydrogen. -- To reduce an equation (Alg.), to bring the unknown quantity by itself on one side, and all the known quantities on the other side, without destroying the equation. -- To reduce an expression (Alg.), to obtain an equivalent expression of simpler form. -- To reduce a square (Mil.), to reform the line or column from the square.

   Syn. -- To diminish; lessen; decrease; abate; shorten; curtail; impair; lower; subject; subdue; subjugate; conquer.