reduction

Noun

reduction (countable and uncountable, plural reductions)

1. The act, process, or result of reducing.
   • With the cutting out of the previous recovery times for electrification work, curtailment of station times and acceleration, considerable reductions have been made in the overall schedules.1961 January, “The North-East London electrification of the Great Eastern Line”, in Trains Illustrated, page 18

   Synonyms:

   decline

2. The amount or rate by which something is reduced, e.g. in price.
   • A 5% reduction in robberies

   Synonyms:

   extract

3. A reaction in which electrons are gained and valence is reduced; often by the removal of oxygen or the addition of hydrogen.
4. The process of rapidly boiling a sauce to concentrate it.
5. The rewriting of an expression into a simpler form.
6. A transformation of one problem into another problem, such as mapping reduction or polynomial-time reduction.
7. An arrangement for a far smaller number of parties, e.g. a keyboard solo based on a full opera.
8. A philosophical procedure intended to reveal the objects of consciousness as pure phenomena. (See phenomenological reduction.)
9. 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

   Synonyms:

   taxis

10. (paying) A reduced price of something by a fraction or decimal.
11. The ratio of a material's change in thickness compared to its thickness prior to forging and/or rolling.
    • The final stage of thickness reduction (typically 90% from about 2mm to <0.2mm) is carried out by cold rolling.2016, Gordon L. Robertson, Food Packaging Principles and Practice, 3rd edition, page 191
12. (historical) 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.