Then and there they gave each other a sound thrashing.

就在那时，他们互相狠狠地殴打在一起。

youdao

If you won't lend it, aunt, I'll be given another sound thrashing for not asking properly. Have pity on your nephew!

婶子若不借，又说我不会说话了，又挨一顿好打呢。婶子只当可怜侄儿罢。

youdao

How the word came to mean a sound thrashing is a mystery.

FORBES: Obama, Democrats, Entomologists and Etymologists Take a Shellacking

The appeals judges gave Jackson a sound judicial thrashing for this failure and for his bizarre and impudent remarks about the richest man in the world, which he made while the case was ongoing.

FORBES: Magazine Article