thresh

Concise Oxford English Dictionary © 2008 Oxford University Press:
thresh/θreʃ/

▶verb

• 1 separate grain from (corn or other crops), typically with a flail or by the action of a revolving mechanism.

• 2 move violently; thrash.

– derivatives
threshing noun.

– origin OE therscan, later threscan, of Gmc origin; cf. thrash.