Definition of "reduction" in English

noun

1. The act, process, or result of reducing.

2. The amount or rate by which something is reduced, e.g. in price.

   • A 5% reduction in robberies

3. (chemistry) A reaction in which electrons are gained and valence is reduced; often by the removal of oxygen or the addition of hydrogen.

4. (cooking) The process of rapidly boiling a sauce to concentrate it.

5. (mathematics) The rewriting of an expression into a simpler form.

6. (computing theory) A transformation of one problem into another problem, such as mapping reduction or polynomial-time reduction.

7. (music) An arrangement for a far smaller number of parties, e.g. a keyboard solo based on a full opera.

8. (philosophy, phenomenology) A philosophical procedure intended to reveal the objects of consciousness as pure phenomena. (See phenomenological reduction.)

9. (medicine) A medical procedure to restore a fracture or dislocation to the correct alignment, usually with a closed approach but sometimes with an open approach (surgery).

   • closed reduction
   • open reduction and internal fixation

10. (paying) A reduced price of something by a fraction or decimal.

11. (metalworking) The ratio of a material's change in thickness compared to its thickness prior to forging and/or rolling.

12. (historical, Roman Catholicism) A religious settlement created during a mission by Spanish or Portuguese colonists with the intent of evangelizing Christianity to the local population.

    • Spanish reductions in Mexico were common during the 18th century.