you (can) bet your (sweet) life)

you (can) bet your (sweet) life)

Absolutely; for sure. The idea that something is so definitely true that you can wager your life on it originated in nineteenth-century America. The San Francisco Sun Dispatch used it in 1852: “He’s around when there’s money . . . bet your life on that.” Other versions are you can bet your bottom dollar, referring to the last of a pile of them, and you can bet your boots (also a valuable item), both of nineteenth-century American provenance, and you bet your (sweet) bippy, a euphemism for you bet your (sweet) ass, which was “bipped” out on television programs. The last two are both mid-twentieth-century Americanisms.
See also: bet
The Dictionary of Clichés by Christine Ammer
See also:
  • like a ton of bricks, (come down)
  • more (to it) than meets the eye
  • go(ing) to town
  • get into the swing of (things), to
  • letter perfect
  • up to scratch, (to come/be)
  • level best, to do one's
  • ask a silly/stupid question (and you'll get a silly/stupid answer)
  • dressed to kill/to the nines
  • chock-a-block, to be