swingle
An implement used to separate the fibres of flax by beating them; a scutch.
The swinging part of a flail, especially that which is used on the grain in threshing; the swipple.
The pole of the Chinese flail is roughly 90 cm. long, the swingle about 30 cm. in length, joined to the pole by a wooden axle projecting at right-angles from the top of the swingle and passing through a loop at the top of the pole[…]
Where it comes from
The noun is from Middle English swingel, from Old English swingel, swingelle (“whip, scourge”), equivalent to swing + -le. Related to Middle Dutch swingel, swengel, Dutch zwingel, zwengel. Doublet of swingel. The verb is from Middle English swingelen, from the noun. Related to Middle Dutch swingelen, swengelen.
Adapted from the Wiktionary entry swingle (CC BY-SA 4.0).