To flail means to wave around wildly. If you are stranded on a deserted island and you see a ship in the distance, it’s a good idea to flail your arms in the air to get the captain’s attention.

Flail originates with the Latin word flagellum, which is a whip. It is also related to the noun flail, a stick with a swinging attachment to it, used to thresh grain. As a verb, it most often refers to arms, but can also involve the whole body, especially if someone is a very wild dancer. Other things can flail as well. If someone admits that his business is flailing, it’s probably lacking direction and not doing very well.

Definitions of flail

n an implement consisting of handle with a free swinging stick at the end; used in manual threshing

Type of:
instrumentation (a piece of equipment or tool) used to effect an end

v move like a flail; thresh about

“Her arms were flailing
Type of:
beat, flap
move with a flapping motion

v give a thrashing to; beat hard

lam, thrash, thresh
bat, clobber, cream, drub, lick, thrash
beat thoroughly and conclusively in a competition or fight
Type of:
beat, beat up, work over
give a beating to; subject to a beating, either as a punishment or as an act of aggression

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