# reduce

/ɹəˈdus/ (US) · /ɹɪdjˈuːs/ (UK)

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

## Senses

### 1. to make smaller

verb · CEFR A2

to make something smaller in size, amount, degree, or price.

For teachers: to diminish the size, quantity, value, or intensity of something. Transitive, requiring a direct object.

- The shop decided to reduce the price of the coats to sell them faster.
- The government implemented new policies to reduce carbon emissions by thirty percent over the next decade.

Usage: Often used with 'by' for amounts or 'to' for a final result.

### 2. to be forced into a state

verb · CEFR B2

to be forced into a worse or simpler situation.

For teachers: to bring someone or something to a lower or more desperate state or condition. Often used in the passive voice.

- After the fire, the family was reduced to living in a small tent.
- The once-mighty empire was reduced to a handful of small islands after the long and costly war.

### 3. cooking

verb · CEFR B2

to boil a liquid so that some of it disappears and the rest becomes thicker.

For teachers: to decrease the volume of a liquid by boiling, thereby concentrating its flavour and increasing its viscosity.

- You should reduce the sauce for ten minutes to make it more flavourful.
- The chef instructed the apprentice to reduce the balsamic vinegar until it reached a syrupy consistency suitable for glazing the duck.

### 4. chemistry

verb · CEFR C1 · Technical

to add electrons to a substance or remove oxygen from it.

For teachers: to cause a substance to gain electrons or lose oxygen during a chemical reaction.

- In this reaction, the iron oxide is reduced to pure iron.
- The process involves reducing the metal ore in a blast furnace to extract the pure element from its oxide form.

### 5. mathematics

verb · CEFR B2 · Academic

to change a fraction or equation into a simpler form.

For teachers: to simplify a mathematical expression or fraction by removing common factors without changing its value.

- The teacher asked the students to reduce the fraction to its simplest form.
- Before solving for the variable, you must reduce the equation by dividing both sides by the common denominator.

### 6. medicine

verb · CEFR C2 · Technical

to put a broken bone or a joint back into its correct place.

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

- The doctor had to reduce the patient's dislocated shoulder in the emergency room.
- The surgeon successfully reduced the compound fracture, ensuring the bone fragments were perfectly aligned before applying the internal fixation.

## Examples

- The shop decided to reduce the price of the shoes.
- The company aims to reduce its carbon footprint by switching to renewable energy sources over the next decade.
- By implementing more efficient manufacturing protocols, the factory managed to reduce waste significantly while simultaneously increasing its total output.

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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.