1. An instrument for threshing or beating grain from the ear by hand, consisting of a wooden staff or handle, at the end of which a stouter and shorter pole or club, called a swipe, is so hung as to swing freely. His shadowy flail hath threshed the corn. (Milton)
2. An ancient military weapon, like the common flail, often having the striking part armed with rows of spikes, or loaded. No citizen thought himself safe unless he carried under his coat a small flail, loaded with lead, to brain the popish assassins. (Macaulay)
Origin: L. Flagellum whip, scourge, in LL, a threshing flail: cf. OF. Flael, flaiel, f. Fleau. See flagellum.