# diesel

/ˈdisəɫ/ (US) · /dˈiːzəl/ (UK)

Source: https://englishreference.com/word/diesel
Updated: 2026-08-15

## Senses

### 1. fuel type

noun · CEFR B1

a heavy oil used as fuel in trucks, buses, and some cars.

For teachers: a heavy petroleum-based fuel used in compression-ignition engines. Uncountable when referring to the substance.

- The truck stopped at the station to fill up with diesel before the long trip.
- Rising costs of crude oil have led to a significant increase in the price of diesel, affecting logistics companies nationwide.

### 2. a vehicle

noun · CEFR B2

a car, truck, or train that has a diesel engine.

For teachers: a vehicle powered by a diesel engine. Countable in this sense.

- He decided to buy a diesel because he drives long distances for work.
- Many European cities are implementing bans on older diesels to improve urban air quality and reduce nitrogen dioxide emissions.

### 3. cannabis

noun · CEFR C2 · Slang

a strong type of the drug cannabis.

For teachers: a specific variety or strain of cannabis known for its pungent, fuel-like aroma.

- The shop was known for selling a specific strain of diesel.
- The cultivar known as Sour Diesel became prominent in the underground market during the late nineties due to its distinct terpene profile.

### 4. engine running on

verb · CEFR C2 · Technical

when an engine keeps running for a moment after you turn it off.

For teachers: the action of a spark-ignition engine continuing to run after the ignition is switched off due to residual heat.

- The old car started to diesel for a few seconds after I took the key out.
- The mechanic explained that the engine was dieseling because of carbon deposits in the combustion chamber that remained hot enough to ignite the fuel.

### 5. engine type

adjective · CEFR B2

relating to an engine that uses diesel fuel.

For teachers: denoting a type of internal combustion engine in which fuel ignition is caused by the elevated temperature of the air in the cylinder due to mechanical compression.

- The diesel engine is usually more efficient than a petrol one for heavy loads.
- The ship's primary propulsion system consists of two massive diesel units capable of generating thousands of horsepower.

## Examples

- Most large trucks run on diesel instead of gasoline.
- The delivery company switched its entire fleet to diesel to improve fuel efficiency on long-distance routes.
- While diesel engines offer superior thermal efficiency compared to petrol counterparts, they have faced increasing regulatory scrutiny due to their higher emissions of nitrogen oxides and particulate matter.

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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.