jack-in-the-box

Noun

jack-in-the-box (plural jacks-in-boxes or jacks-in-the-boxes or jack-in-the-boxes or jacks-in-the-box)

1. Children’s toy consisting of a small box from which a male figure pops out unexpectedly after some turnings of a crank.
   • "Did you venture to call me a liar?" ("No, sir, no!" shouted the accused, and disappeared like a Jack-in-the-box.)1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC
   • “There’s this terrible business to start with. Scotland Yard men in and out of the house like a jack-in-the-box! Never know where they won’t turn up next.”1920, Agatha Christie, The Mysterious Affair at Styles, London: Pan Books, published 1954, page 126
2. (historical) A small but powerful kind of screw, used by burglars to break open safes.
   • It was possible, from underneath, to use the old jack-in-the-box safe-breaker's tool which lay in his gasman's bag.2013, Donald Thomas, The Secret Cases of Sherlock Holmes
3. (obsolete) A con-man who deceived tradesmen by substituting empty boxes for others full of money.