A fin at the posterior extremity of a fish's body, typically continuous with the tail.
- ‘The tail fin of most ray-finned fish, with the exception of sturgeons and paddlefish, is homocercal, nearly symmetrical about the midline.’
- ‘The overall appearance of the fish is similar to that of a small shark, given the shape of the body, the powerful tail fin, and the elevated anterior portion of the second dorsal fin.’
- ‘Mechanical testing of the tadpole tail fin has revealed that the fin is viscoelastic and stiffer in small rather than large deformations.’
- ‘These early lobe-fins were fast-swimmers with a heterocercal tail, meaning that the tail fin was asymmetrical and larger on the dorsal side.’
- ‘In his effort to capture a female's attention, he puffs out his cheeks, mouth, and gill chambers by filling them with air; he also arches his back, points his tail fin, and sinuously wriggles his body.’
A projecting vertical surface on the tail of an aircraft, providing stability and typically housing the rudder.
- ‘Though not yet covered, the tail fin, rudder, horizontal stabilizer and elevator are all built.’
- ‘Shocked travellers described how the larger Boeing 767 shook from side to side as its wing ripped off a tail fin from the smaller aircraft.’
- ‘The aircraft structure incorporates larger strakes below the rear section of the fuselage below the position of the tail fin.’
- ‘The radar warning receiver is mounted in the tail fin.’
- ‘The variable sweep wing and the twin almost upright tail fins of the F - 14 Tomcat give the aircraft its distinctive appearance.’
3An upswept projection on each rear corner of a car, popular in the 1950s.
- ‘Even if people hardly knew who Harley Earl was, they associated tail fins with General Motors.’
- ‘Earl went on to influence design by giving recognisable features to cars such as chrome, tail fins, curved windshields, and the infamous Motoramas.’
- ‘There was nothing in the marketplace of the 1950s that indicated a desire for tail fins on cars in the U.S. and Europe.’
- ‘Even the Model T (form and function in perfect balance) would evolve into a gas-guzzler with tail fins.’
- ‘The house used to be turquoise; my dad drove a turquoise Merc with tail fins.’