v. & n.
v. 1 tr. beat severely, esp. with a stick or whip. 2 tr. defeat thoroughly in a contest. 3 intr. (of a paddle wheel, branch, etc.) act like a flail; deliver repeated blows. 4 intr. (foll. by about, around) move or fling the limbs about violently or in panic. 5 intr. (of a ship) keep striking the waves; make way against the wind or tide (thrash to windward). 6 tr. = THRESH 1.
n. 1 an act of thrashing. 2 colloq. a party, esp. a lavish one. thrash out discuss to a conclusion. thrashing n.
[ OE therscan, later threscan, f. Gmc ]