an interjection of either amazed awe or sudden anger/despondency; from the terms, "Christ's wounds," and/or "Christ's blood," which were deemed sacreligious and so were shortened to "bloody;" "hell was added later to express the full extent of the emotion; originated in Great Britain
Denethor: *insane and unconsolable* Flee, flee for your liiiiives!
Gandalf: *irritated* Oh, bloody HELL! *whacks Denethor with his staff*
Hermione: *punches Malfoy in his snivelling face* Bloody hell, I've wanted to do that for ages!