fin

1
[ fin ]
See synonyms for fin on Thesaurus.com
noun
  1. a membranous, winglike or paddlelike organ attached to any of various parts of the body of fishes and certain other aquatic animals, used for propulsion, steering, or balancing.

  2. Nautical.

    • a horizontal, often adjustable, winglike appendage to the underwater portion of a hull, as one for controlling the dive of a submarine or for damping the roll of a surface vessel.

  1. Also called vertical stabilizer .Aeronautics. any of certain small, subsidiary structures on an aircraft, designed to increase directional stability.

  2. any of a number of standing ridges on an ordinarily hot object, as a radiator, a cylinder of an internal-combustion engine, etc., intended to maximize heat transfer to the surrounding air by exposing a large surface area.

  3. any part, as of a mechanism, resembling a fin.

  4. Metallurgy. a ridge of metal squeezed through the opening between two rolls, dies, or halves of a mold in which a piece is being formed under pressure.: Compare flash (def. 11).

  5. Automotive. an ornamental structure resembling an aeronautical fin that is attached to the body of an automobile, as on each rear fender (tail fin ).

  6. Slang. the arm or hand.

  7. Usually fins. flipper (def. 2).

verb (used with object),finned, fin·ning.
  1. to cut off the fins from (a fish); carve or cut up, as a chub.

  2. to provide or equip with a fin or fins.

verb (used without object),finned, fin·ning.
  1. to move the fins; lash the water with the fins, as a whale when dying.

Origin of fin

1
First recorded before 1000; Middle English, Old English finn; cognate with Dutch vin, Low German finne; akin to Swedish fena; probably akin to Latin pinna; see also pen1

Other words from fin

  • finless, adjective
  • finlike, adjective

Other definitions for fin (2 of 4)

fin2
[ fin ]

noun
  1. Slang. a five-dollar bill.

Origin of fin

2
First recorded in 1865–70; earlier finnip, finnup, fin(n)if “a five-pound note,” from Yiddish fin(e)f “five,” from Middle High German vumf, vimf; see origin at five

Other definitions for fin. (3 of 4)

fin.

abbreviation
  1. finance.

  2. financial.

  1. finish.

Other definitions for Fin. (4 of 4)

Fin.

abbreviation
  1. Finland.

  2. Finnish.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use fin in a sentence

  • It would not have been difficult to imagine in the midst of that swelling mass the shapes of fins and gill-coverings.

    Toilers of the Sea | Victor Hugo
  • Turning movements are brought about by use of the lateral fins in much the same way as a boat is turned.

    A Civic Biology | George William Hunter
  • The paired fins are four in number, and are believed to correspond in position and structure with the paired limbs of a man.

    A Civic Biology | George William Hunter
  • We notice the dorsal and other single fins are evidently useful in balancing and steering.

    A Civic Biology | George William Hunter
  • Yes, really and truly, these little fish fly or sail through the air, for their fins balance them like a parachute.

    Stories of California | Ella M. Sexton

British Dictionary definitions for fin (1 of 5)

fin1

/ (fɪn) /


noun
  1. any of the firm appendages that are the organs of locomotion and balance in fishes and some other aquatic animals. Most fishes have paired and unpaired fins, the former corresponding to the limbs of higher vertebrates

  2. a part or appendage that resembles a fin

    • British a vertical surface to which the rudder is attached, usually placed at the rear of an aeroplane to give stability about the vertical axis: US name: vertical stabilizer

    • a tail surface fixed to a rocket or missile to give stability

  1. nautical a fixed or adjustable blade projecting under water from the hull of a vessel to give it stability or control

  2. a projecting rib to dissipate heat from the surface of an engine cylinder, motor casing, or radiator

  3. (often plural) another name for flipper (def. 2)

verbfins, finning or finned
  1. (tr) to provide with fins

  2. (tr) to remove the fins from (a dead fish)

  1. (intr) (esp of a whale) to agitate the fins violently in the water

Origin of fin

1
Old English finn; related to Middle Dutch vinne, Old Swedish fina, Latin pinna wing

Derived forms of fin

  • finless, adjective

British Dictionary definitions for fin (2 of 5)

fin2

/ (fɪn) /


noun
  1. US slang a five-dollar bill

Origin of fin

2
from Yiddish finf five, ultimately from Old High German funf, finf

British Dictionary definitions for Fin (3 of 5)

Fin

abbreviation for
  1. Finland

  2. Finnish

British Dictionary definitions for FIN (4 of 5)

FIN

abbreviation for
  1. Finland (international car registration)

British Dictionary definitions for fin. (5 of 5)

fin.

abbreviation for
  1. finance

  2. financial

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for fin

fin

[ fĭn ]


  1. One of the winglike or paddlelike parts of a fish, dolphin, or whale that are used for propelling, steering, and balancing in water.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.