Thrash, Thresh, v. t. [imp. & p. p. Thrashed; p. pr. & vb. n. Thrashing.]
Etymology: [OE. , , to beat, AS. , ; akin to D. dorschen, OD. derschen, G. dreschen, OHG. dreskan, Icel. , Sw. tröska, Dan. tærske, Goth. , Lith. traszketi to rattle, Russ. treskate to burst, crackle, tresk' a crash, OSlav. troska a stroke of lighting. Cf. Thresh.]
1. To beat out grain from, as straw or husks; to beat the straw or husk of (grain) with a flail; to beat off, as the kernels of grain; as, to thrash wheat, rye, or oats; to thrash over the old straw. The wheat was reaped, thrashed, and winnowed by machines. H. Spencer.
2. To beat soundly, as with a stick or whip; to drub.
1 other Webster entry under this spelling
Thrash, Thresh, v. t.
1. To practice thrashing grain or the like; to perform the business of beating grain from straw; as, a man who thrashes well.
2. Hence, to labor; to toil; also, to move violently. I rather would be Mævius, thrash for rhymes, Like his, the scorn and scandal of the times. Dryden.
Shades of meaning
Fernald has no entry of its own for thrash; he lists it under beat.
Where he writes about it:
Others of the above words describe the manner of beating, as bastinado, to beat on the soles of the feet; belabor, to inflict a comprehensive and exhaustive beating; cudgel, to beat with a stick; thrash, as wheat was beaten out with the old hand-flail; to pound (akin to L. pondus, a weight) is to beat with a heavy, and pommel with a blunt, instrument. — from beat