why on earth

why on earth

Used to ask a question that emphasizes one's shock, anger, disgust, incredulity, etc. Why on earth are they here when the party doesn't start for hours? Why on earth would I want a table that doesn't even stand up anymore? We're just about to sit down for dinner, so why on earth would you give the kids candy now?
See also: earth, on, why
Farlex Dictionary of Idioms.
See also:
  • why in God's name
  • why doesn't (one) (do something)
  • why don't you?
  • say over
  • be on the market
  • why, oh why
  • why ever
  • why ever...?
  • It's anybody's guess
  • it's anybody's/anyone's guess