what the Devil

English edit

(idiomatic) Used to add emphasis to “what” when beginning a question.
What the Devil have you done to the horse?
- c. 1515–1516, John Skelton, Magnyfycence; republished in John Scattergood, editor, John Skelton: The Complete English Poems, 1983, →OCLC, page 166, line 922:
  What the devyll hast thou on thy fyste? An owle?

used to add emphasis to "what" when beginning question