I. ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: Middle English fish tail
1. : something suggesting the tail of a fish especially in being somewhat triangular with a median notch: as
a. : an arrow that wobbles in flight
b. : a railroad semaphore the arm of which is notched at the end and which is used as an advance warning signal
2. : a turning ballroom step
3. : the aeronautical maneuver of fishtailing
II. adjective
also fishtailed ˈ ̷ ̷ˌ ̷ ̷
: having a shape that imitates or resembles the shape of a fish's tail
a gardener's knife with a sharp fishtail blade — New Yorker
the fishtail gas jets in the square-sided station lamps — Anthony West
some of the women were wound up in fishtail skirts which defy description — G.H.Reed b.1887
III. intransitive verb
1. : to swing the tail of an airplane from side to side during a glide without altering the flight path in order to reduce speed in approaching the ground for a landing
2. of a ship : to move through the water with a side-to-side or whipping motion of the stern
the short-ranged sleek destroyer fishtailing alongside — K.M.Dodson