/thresh/ , v.t.
1. to separate the grain or seeds from (a cereal plant or the like) by some mechanical means, as by beating with a flail or by the action of a threshing machine.
2. to beat as if with a flail.
v.i.
3. to thresh wheat, grain, etc.
4. to deliver blows as if with a flail.
5. thresh out or over . See thrash (def. 8).
n.
6. the act of threshing.
Also, thrash .
[ bef. 900; ME threschen, thresshen, OE threscan; c. G dreschen, Goth thriskan; akin to D dorsen, ON thriskja ]