fishtail

UK: /ˈfɪʃˌteɪl/ US: (fish′tāl′)

WordReference Random House Unabridged Dictionary of American English © 2025

fish•tail  (fish′tāl′), v.i. 

1. to swerve or skid from side to side, as the rear end of a car.
2. Aeronautics to slow an airplane by causing its tail to move rapidly from side to side.

n. 

3. Aeronautics such a maneuver.
4. Chemistry a gas burner having two jets crossing each other so as to produce a flame resembling a fish's tail.
5. Chemistry a device having a long, narrow slot at the top, placed over a gas jet, as of a Bunsen burner, to give a thin, fanlike flame.
6. Jewelry a setting consisting of four prominent triangular corner prongs to hold the stone.

• late Middle English. See fish, tail¹ 1400–50

Collins Concise English Dictionary © HarperCollins Publishers::

fishtail / ˈfɪʃˌteɪl/ noun

1. an aeroplane manoeuvre in which the tail is moved from side to side to reduce speed
2. a nozzle having a long narrow slot at the top, placed over a Bunsen burner to produce a thin fanlike flame