# reduction

/ɹəˈdəkʃən/ (US) · /ɹɪdˈʌkʃən/ (UK)

Source: https://englishreference.com/word/reduction
Updated: 2026-06-19

## Senses

### 1. making something smaller

noun · CEFR B1

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

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

- The company announced a major reduction in plastic waste this year.
- The government is under pressure to implement a significant reduction in carbon emissions to meet international environmental targets.

### 2. lower price

noun · CEFR A2

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

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

- There is a 20% reduction on all winter coats today.
- The retailer offered a substantial reduction on last season's inventory to clear space for the incoming spring collection.

### 3. thickening a sauce

noun · CEFR B2

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

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

- The chef made a balsamic reduction to drizzle over the salad.
- Simmer the stock until it achieves a syrupy consistency, as a proper reduction is essential for a rich red-wine sauce.

### 4. gaining electrons

noun · CEFR C1 · Technical

a chemical reaction where a substance gains electrons.

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

- In this experiment, the reduction of copper oxide produces pure copper.
- The process of smelting involves the chemical reduction of metal ores to extract the pure metallic element.

### 5. fixing a bone

noun · CEFR C1 · Technical

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

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

- The doctor performed a manual reduction to fix the patient's dislocated shoulder.
- If the fracture is unstable, an open reduction with internal fixation may be required to ensure proper healing of the bone.

### 6. simplified music

noun · CEFR C1 · Technical

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

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

- The students practiced using a piano reduction of the full orchestral score.
- The composer provided a keyboard reduction of the concerto to facilitate rehearsals before the full orchestra was available.

### 7. simplifying an expression

noun · CEFR B2 · Academic

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

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

- The teacher explained the reduction of fractions to their lowest terms.
- The proof relies on the reduction of the complex equation to a series of linear inequalities.

## Examples

- The store is offering a big reduction in prices this week.
- The government announced a significant reduction in carbon emissions to meet its environmental targets by the end of the decade.
- In culinary arts, a reduction involves simmering a liquid until it thickens, thereby intensifying the flavors through the evaporation of water content.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.