Definition of "jack-in-the-box" in English

noun

1. Children’s toy consisting of a small box from which a male figure pops out unexpectedly after some turnings of a crank.

2. (historical) A small but powerful kind of screw, used by burglars to break open safes.

3. (obsolete) A con-man who deceived tradesmen by substituting empty boxes for others full of money.