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  • fin
    fin
    noun
    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.
  • fin.
    fin.
    abbreviation
    finance.
  • Fin.
    Fin.
    abbreviation
    Finland.
  • FIN
    FIN
    abbreviation
    Finland (international car registration)
  • Fin
    Fin
    abbreviation
    Finland
Synonyms

fin

1 American  
[fin] / fɪn /

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.

    1. 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.

    2. fin keel.

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

  4. 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.

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

  6. 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.

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

  8. Slang. the arm or hand.

  9. Usually fins. flipper.


verb (used with object)

  • fins,
    present (3rd person singular)
  • finned,
    past participle,  past
  • finning
    present participle
  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)

  • fins,
    present (3rd person singular)
  • finned,
    past participle,  past
  • finning
    present participle
  1. to move the fins; lash the water with the fins, as a whale when dying.

fin 2 American  
[fin] / fɪn /

noun

  1. Slang. a five-dollar bill.


fin. 3 American  

abbreviation

  1. finance.

  2. financial.

  3. finish.


Fin. 4 American  

abbreviation

  1. Finland.

  2. Finnish.


FIN 1 British  

abbreviation

  1. Finland (international car registration)

"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

Fin 2 British  

abbreviation

  1. Finland

  2. Finnish

"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

fin. 3 British  

abbreviation

  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

fin 4 British  
/ fɪn /

noun

  1. slang a five-dollar bill

"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

fin 5 British  
/ 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

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

    2. a tail surface fixed to a rocket or missile to give stability

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

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

  5. (often plural) another name for flipper

"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

verb

  1. (tr) to provide with fins

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

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

"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
fin Scientific  
/ 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.


Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future


Etymology

Origin of fin1

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 ( def. ); see also pen 1 ( def. )

Origin of fin2

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


Explanation

A fin is the part of a fish's body that protrudes into the water and helps it balance and move in various directions. Sharks use their dorsal fins to stabilize their bodies as they propel through the water. Fish, whales, dolphins, and other aquatic animals have fins on various parts of their bodies. Surfboards often have a rear fin that works in a similar way, helping to keep the board steady and aid in making turns. Ships, cars, and aircraft also have fins that assist with balance. In Old English, it was finn, which probably comes from the Latin pinna, "feather or wing."

Keep Reading on Vocabulary.com

Vocabulary lists containing fin

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Known as The Flying Kangaroo for the logo displayed on its tail fin and elsewhere, Qantas has already scheduled its first nonstop Sydney-to-London flight for October 2027.

From The Wall Street Journal ● Sep. 23, 2026

An estimated 4,000 humpback whales, 6,000 fin whales and 6,000 minke whales visited the Greenland Sea in the summer of 2024.

From BBC ● Aug. 20, 2026

This isn’t the only thing going on this summer that gives me that ominous fin de siècle feeling.

From MarketWatch ● Aug. 12, 2026

For these reasons, the AI IPOs have less a forward-looking than a fin de siècle aura about them.

From Los Angeles Times ● Jun. 23, 2026

He had seen the second fin now coming up behind the first and had identified them as shovel-nosed sharks by the brown, triangular fin and the sweeping movements of the tail.

From "The Old Man and The Sea" by Ernest Hemingway

After long observation and many trials they decided that fin. strips of metal screening tacked to the ceiling are what flies like best.

From Time Magazine Archive

“Look at the fin. Floppy on top. It’s not a shark.”

From "Shouting at the Rain" by Lynda Mullaly Hunt

“That’s when I lost part of my tail and cracked my fin. Not a big deal when I’m in fish form, but it’s a bit inconvenient here at Sea Bottom.”

From "When the Sea Turned to Silver" by Grace Lin

II, 5 ad fin., note.316.Cf. note on Cuichelm, II, 9.

From Bede's Ecclesiastical History of England by Cuthbert Bede

III, 3, ad fin., note.558.Innisboffin, off the coast of Mayo.

From Bede's Ecclesiastical History of England by Cuthbert Bede

Moss and Njemile were getting off at the MacArthur station the next morning when Njemile said, “I declare this year over. Fin. Cerrado. Done.”

From "Anger Is a Gift" by Mark Oshiro

Fin. i. 16, like ὠφέλημα; whereas quæstus and compendium denote gain in the course of trade; quæstus, rather the steadily continued gains of a regular occupation, earnings, in opp. to sumptus; Cic.

From Döderlein's Hand-book of Latin Synonymes by Ludwig Döderlein

In the Hortensius Cicero appeared as the champion of philosophy: De Fin. i.

From The Student's Companion to Latin Authors by George Middleton

Translations from Greek poets occur in the philosophical works, e.g. de Fin. v.

From The Student's Companion to Latin Authors by George Middleton

“Nothing of the kind,” said Fin., drying his eyes, and endeavouring to look sorry and sentimental.

From Humours of Irish Life by Various

“We figured out a day before we started shooting that these things don’t quite marry up,” said Johnstone, who turned to FIN Design and Effects of Australia to blend his M3GANs together.

From Los Angeles Times ● Jan. 7, 2023

USA 1-0 FIN 20:00 That’s the end of the period — the goal from defenseman Faulk, a Carolina prospect who now plays for Minnesota-Duluth, is all the scoring in a relatively tame opening stanza.

From New York Times ● Dec. 27, 2010

USA 3-2 FIN … two points for the Amerks, one for the Finns.

From New York Times ● Dec. 27, 2010

In fact, "Breathless" is dedicated to Monogram Pictures, an American studio that specialized in grade-B crime dramas, and carries no other credits: only the title at the beginning and the word "FIN" at the end.

From Salon ● May 29, 2010

They may be distinguished from sei whales in the following similar ways: Fin WhaleSei WhaleDORSAL FIN Slightly falcate, forms angle of less than 40° with back slightly more than one-third forward from tail.

From Whales, Dolphins, and Porpoises of the Western North Atlantic A Guide to Their Identification by David Caldwell

Several high-profile players, such as England fly-halves George Ford and Fin Smith, opted to stay with their current clubs, rather than take up interest from R360.

From BBC ● Sep. 25, 2026

They said it could rise even higher if Salesforce’s acquisitions of Contentful and Fin close in the upcoming weeks.

From MarketWatch ● Aug. 27, 2026

Britain's Fin Tarling, 19, died during the Volta a Portugal on Friday following a high-speed collision with a van which had strayed on to the closed road.

From BBC ● Aug. 18, 2026

Fin Colleton spent the early days of the pandemic like many: alone in an empty house, isolated from anyone for months at a stretch.

From The Wall Street Journal ● Aug. 4, 2026

There were some things she missed from the Academy: the sea, and Maesie and Fin, and her friends.

From "Huntress" by Malinda Lo

“He has fins, as people say in this thing.”

From The Wall Street Journal ● Aug. 29, 2026

The shark made a few circles, its fins at times breaching the water’s surface as stunned fishermen looked on.

From Los Angeles Times ● Aug. 15, 2026

More high-quality footage is needed, particularly clear views of dorsal fins and eye patches, which can be used to identify individual animals.

From Science Daily ● Jul. 23, 2026

But the fins are swooped up by traders for the international markets, where they are used in shark-fin soup.

From Barron's ● Jul. 23, 2026

I wasn’t certain what I was looking at, but whatever it was, I wanted to compare the area of the fins with the area of the tubing.

From "October Sky" by Homer Hickam

The fossils belonged to an extinct group of finned octopuses known as Cirrata.

From Science Daily ● Apr. 25, 2026

Lowe, who has been studying the behavior of juvenile great white sharks along the Southern California coast for 20 years, was not surprised by the appearance of a finned friend.

From Los Angeles Times ● Mar. 26, 2026

Magnus wrote in his 1555 book they were 200-feet long with broad, forked tails and finned feet, with faces resembling warthogs and dual blow-holes on the top of their heads.

From National Geographic ● Dec. 28, 2023

State media released a photo of a missile mounted with a finned, cone-shaped payload soaring into the air while leaving a trial of bright orange flames.

From Seattle Times ● Sep. 28, 2021

He could feel the rumble of the craft’s engines tilling the air but couldn’t make out the silver skin, the sweeping ribs, the finned tail.

From "Unbroken" by Laura Hillenbrand

A global onslaught of legislation followed to limit shark catch-and-eliminate finning, widely regarded as a cruel and wasteful fishing method.

From Science Magazine ● Jan. 10, 2024

What’s more, illegal finning for export to Asia still remains a major concern in Brazil, with Brazilian authorities reporting in late June that they’d seized an enormous haul of illegally obtained shark fins.

From National Geographic ● Jul. 17, 2023

The practice of shark finning, whereby sharks are caught for their fins and their carcasses then dumped back into the ocean, has been banned in U.S. waters for decades.

From Seattle Times ● Dec. 16, 2022

Apparently neither the petition creators nor the many signatories are aware that we already banned shark finning across the United States almost 30 years ago.

From Scientific American ● May 24, 2022

The sale had not long been concluded, and the little community were preparing to obey Acton's order to "Come outside," when the latter rushed into the room finning with rage.

From The Triple Alliance Its trials and triumphs by Harold Avery

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