Definition of "thrash" in English

verb

To beat mercilessly.
To defeat utterly.
To thresh.
To move about wildly or violently; to flail; to labour.
(software) To extensively test a software system, giving a program various inputs and observing the behavior and outputs that result.
(computing) In computer architecture, to cause or undergo poor performance of a virtual memory (or paging) system.

noun

(countable) A beat or blow; the sound of beating.
(rail transport, uncountable) The roar and smoke of a particularly powerful diesel engine.
(music, uncountable) Ellipsis of thrash metal.