English Reference
noun

reduction

n.
US /ɹəˈdəkʃən/ UK /ɹɪdˈʌkʃən/ re·duc·tion UK spelling reduction's, reduction's

  1. 01 B1 Intermediate

    the act of making something smaller in size, amount, or degree.

    the act or process of decreasing something in size, amount, intensity, or degree.

    Simple

    The company announced a major reduction in plastic waste this year.

    In context

    The government is under pressure to implement a significant reduction in carbon emissions to meet international environmental targets.

    decreasecutdiminution
  2. 02 A2 Elementary

    a lower price for something, like a discount in a shop.

    the amount by which a price or value is lowered; a discount.

    Simple

    There is a 20% reduction on all winter coats today.

    In context

    The retailer offered a substantial reduction on last season's inventory to clear space for the incoming spring collection.

    discountmarkdownrebate
  3. 03 B2 Upper Intermediate Cooking

    the process of boiling a liquid quickly to make it thicker and stronger in flavour.

    the process of thickening and intensifying the flavour of a liquid mixture through rapid evaporation.

    Simple

    The chef made a balsamic reduction to drizzle over the salad.

    In context

    Simmer the stock until it achieves a syrupy consistency, as a proper reduction is essential for a rich red-wine sauce.

  4. 04 C1 Advanced Technical Science

    a chemical reaction where a substance gains electrons.

    a chemical reaction involving the gain of electrons by a substance, often accompanied by the loss of oxygen.

    Simple

    In this experiment, the reduction of copper oxide produces pure copper.

    In context

    The process of smelting involves the chemical reduction of metal ores to extract the pure metallic element.

  5. 05 C1 Advanced Technical Medicine

    a medical procedure to put a broken bone back into the right place.

    a surgical or manual procedure used to restore a fracture or dislocation to its correct anatomical alignment.

    Simple

    The doctor performed a manual reduction to fix the patient's dislocated shoulder.

    In context

    If the fracture is unstable, an open reduction with internal fixation may be required to ensure proper healing of the bone.

  6. 06 C1 Advanced Technical Music

    a simpler version of a piece of music, like an opera played only on a piano.

    an arrangement of a musical work for a smaller number of instruments than the original.

    Simple

    The students practiced using a piano reduction of the full orchestral score.

    In context

    The composer provided a keyboard reduction of the concerto to facilitate rehearsals before the full orchestra was available.

  7. 07 B2 Upper Intermediate Academic Math

    the act of rewriting a math problem or expression into a simpler form.

    the rewriting of a mathematical expression or problem into a simpler or more fundamental form.

    Simple

    The teacher explained the reduction of fractions to their lowest terms.

    In context

    The proof relies on the reduction of the complex equation to a series of linear inequalities.

Usage reduction lead · show reduction · significant reduction

Photograph: Murdo MacLeod/The Guardian The move is part of a plan drawn up by Keir Starmer’s government to fast-track the reduction of animals in research.

The Guardian· 12 Aug 2026

Solar power has seen dramatic cost reductions thanks to mass production.

BBC News· 15 Apr 2026

From Middle English reduccion, a borrowing from Old French reducion, from Latin reductiō, reductiōnem. Equivalent to reduce + -tion.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin reductio
Level B2 · Upper Intermediate
Frequency Common
Updated