English Reference
noun · verb · adjective

diesel

n. · v. · adj.
US /ˈdisəɫ/ UK /dˈiːzəl/ diesel UK spelling diesels

  1. 01 B1 Intermediate

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

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

    Simple

    The truck stopped at the station to fill up with diesel before the long trip.

    In context

    Rising costs of crude oil have led to a significant increase in the price of diesel, affecting logistics companies nationwide.

    fuelgas oil
  2. 02 B2 Upper Intermediate

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

    n.a vehicle powered by a diesel engine. Countable in this sense.

    Simple

    He decided to buy a diesel because he drives long distances for work.

    In context

    Many European cities are implementing bans on older diesels to improve urban air quality and reduce nitrogen dioxide emissions.

    diesel vehicle
  3. 03 C2 Proficiency Slang

    n.a strong type of the drug cannabis.

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

    Simple

    The shop was known for selling a specific strain of diesel.

    In context

    The cultivar known as Sour Diesel became prominent in the underground market during the late nineties due to its distinct terpene profile.

    sour diesel
  4. 04 C2 Proficiency Technical Technical

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

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

    Simple

    The old car started to diesel for a few seconds after I took the key out.

    In context

    The mechanic explained that the engine was dieseling because of carbon deposits in the combustion chamber that remained hot enough to ignite the fuel.

    run ondieseling
  5. 05 B2 Upper Intermediate Science

    adj.relating to an engine that uses diesel fuel.

    adj.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.

    Simple

    The diesel engine is usually more efficient than a petrol one for heavy loads.

    In context

    The ship's primary propulsion system consists of two massive diesel units capable of generating thousands of horsepower.

    compression ignition

The sale of new petrol and diesel cars is then to be banned from 2035.

The Guardian· 14 Aug 2026

The attacks have also led Russia to ban diesel fuel exports – which, before 2022, supplied half of Europe’s diesel.

The Conversation· 4 Aug 2026
This entry
Level B2 · Upper Intermediate
Frequency Common
Updated