To keep safe; to defend; to guard; to prevent harm coming to.
To book a passenger on a later flight if there is a chance they will not be able to board their earlier reserved flight.
To move about wildly or violently; to flail; to labour.
To defeat utterly.
To extensively test a software system, giving a program various inputs and observing the behavior and outputs that result.
In computer architecture, to cause or undergo poor performance of a virtual memory (or paging) system.
To beat mercilessly.
To thresh.
A beat or blow; the sound of beating.
thrash metal