English Reference
noun · verb

fin

n. · v.
US /ˈfɪn/ UK /fˈɪn/ fin UK spelling fin's, fin's

  1. 01 A2 Elementary

    n.a thin, flat part that sticks out from the body of a fish to help it swim and balance.

    n.an organ of a fish or cetacean used for propulsion, steering, or balancing in water.

    Simple

    The shark's dorsal fin appeared above the water as it swam near the boat.

    In context

    Marine biologists can often identify individual whales by the unique notches and scars found on their dorsal fins.

  2. 02 B1 Intermediate Sport

    n.a long, flat rubber shoe that you wear to swim faster underwater.

    n.a flipper-like device worn on the feet to increase propulsion while swimming or diving.

    Simple

    You should wear fins and a mask if you want to go snorkeling.

    In context

    The diver kicked his fins powerfully to reach the coral reef before the current shifted.

  3. 03 B2 Upper Intermediate Technical Technical

    n.a flat part on a plane, rocket, or machine that helps it stay steady or cool down.

    n.a fixed or adjustable vane used for aerodynamic stability or to increase the surface area for heat dissipation.

    Simple

    The small fins on the back of the rocket help it fly straight.

    In context

    The engine's cooling fins were clogged with dust, causing the internal temperature to rise dangerously during the long flight.

  4. 04 C1 Advanced SlangBritish EnglishAmerican English

    n.a slang word for a five-pound note or five dollars.

    n.a slang term for a five-unit currency note, specifically five pounds in the UK or five dollars in the US.

    Simple

    He handed the shopkeeper a fin to pay for the magazine.

    In context

    In the old detective novel, the protagonist slipped the informant a fin in exchange for the address of the warehouse.

  5. 05 C1 Advanced Technical

    v.to cut the fins off a fish, especially a shark.

    v.to remove the fins from a fish, often used in the context of the controversial practice of shark finning.

    Simple

    Many countries have banned the practice of finning sharks at sea.

    In context

    The environmental agency reported that thousands of sharks are illegally finned every year to satisfy the demand for specialty soups.

This entry
Level A2 · Elementary
Frequency Frequent
Updated