1 the cardinal number that is the sum of four and one [syn: five, 5, V, cinque, quint, quintet, fivesome, quintuplet, pentad, Phoebe, Little Phoebe]
2 one of a pair of decorations projecting above the rear fenders of an automobile [syn: tail fin, tailfin]
3 one of a set of parallel slats in a door or window to admit air and reject rain [syn: louver, louvre]
4 a shoe for swimming; the paddle-like front is an aid in swimming (especially underwater) [syn: flipper, flippers, fins]
5 a stabilizer that resembles the fins of a fish
6 organ of locomotion and balance in fishes and some other aquatic animals
1 equip (a car) with fins
2 propel oneself through the water in a finning motion
3 show the fins above the water while swimming; "The sharks were finning near the surface" [syn: break water] [also: finning, finned]
- One of the appendages of a fish, used to propel itself and to manoeuvre/maneuver.
- A similar appendage of a cetacean or other marine animal.
- A thin, rigid component of an aircraft, extending from the fuselage and used to stabilise and steer the aircraft.
- A similar structure on the tail of a bomb, used to help keep it on course.
- A hairstyle, resembling the fin of a fish, in which the hair is combed and set into a vertical ridge along the top of the head from about the crown to the forehead.
- A device worn by divers and swimmers on their feet.
- An extending part on a surface of a radiator, engine, heatsink, etc., used to facilitate cooling.
- (U.S. slang) A five-dollar bill
appendage of a fish
appendage of a cetacean or other marine animal
of a bomb
- Dutch: vin
- French: empennage
- Italian: impennaggio
- Russian: стабилизатор
- Norwegian: hanekam
device used by divers
thumb|200px|Arrow fletches are a type of fin.A fin is a surface used to produce lift and thrust or to steer while traveling in water, air, or other fluid media. The first use of the word was for the limbs of fish, but has been extended to include other animal limbs and man-made devices.
The foremost use of fins is to ensure the directional stability of an object moving through a fluid such as water or air and may be seen in the use of fletching on arrows and fins at the rear of some missiles, rockets, self-propelled torpedoes, and kinetic energy penetrators. They are typically "planar" (shaped like small wings), although grid fins are sometimes used in specialized cases.
Moving fins may be used to propel an object through lateral thrust (see mechanics).
Examples of fin use:
- Propellers usually have a number of fins that work to translate torquing force to lateral thrust, thus propelling a ship. These are also called blades. In the case of high power application it is important to avoid cavitation, caused by excessive negative pressure, as this can cause noise, a loss of power, and damage to the propeller.
- For scuba divers' fins, see swimfin.
- In surfing, a skeg is a stabilizing fin located at the rear of the surfboard. A skeg has the effect of keeping the board moving forward in a controlled manner. The surfboard fin has undergone numerous phases of development.
- Constructions of the same purpose as fins (producing thrust, but working in gaseous media) instead are usually called wings or stabilizers with aerodynamics as the governing science. The exception to this is the vertical surface of an aircraft to which the rudder is attached - this is still usually called a fin but is (more formally) called a vertical stabilizer.
- the fin of a rocket uses pressure on both sides of the fin to create a more stable flight in a rocket
fin in German: Finne (Wassersport)
fin in French: Nageoire
fin in Ido: Floso
fin in Lithuanian: Pelekas
fin in Dutch: Vin
fin in Ukrainian: Плавець
fin in Spanish: aleta
fin in Portuguese: barbatana
Australian crawl, C, C-note, G, G-note, Little Phoebe, Pentateuch, Phoebe, V, aquaplaning, aquatics, backstroke, balneation, bathe, bathing, breaststroke, buck, butterfly, cartwheel, cent, century, cinque, copper, crawl, dime, diving, dog paddle, dollar, dollar bill, fifty cents, fish, fishtail, five, five bucks, five cents, five dollars, five hundred dollars, five-dollar bill, five-hundred-dollar bill, five-spot, fiver, fivesome, flapper, flipper, floating, four bits, frogskin, grand, half G, half a C, half dollar, half grand, hundred-dollar bill, iron man, mill, mullet, natation, nickel, penny, pentachord, pentad, pentagon, pentagram, pentahedron, pentameter, pentapody, pentarchy, pentastich, pentathlon, quarter, quincunx, quint, quintet, quintuplet, red cent, sawbuck, sidestroke, silver dollar, skin, smacker, surfboarding, surfing, swim, swimming, ten cents, ten-spot, tenner, thousand dollars, thousand-dollar bill, treading water, twenty-dollar bill, twenty-five cents, two bits, two-dollar bill, two-spot, wading, waterskiing, yard