jack-in-the-box (jāk'ĭn-thə-bŏks') n.
pl.jack-in-the-box·es or jacks-in-the-box (jāks'-) A toy consisting of a clownlike puppet that springs out of a box when the lid is activated.
1570, originally a name for a sharp or cheat, "who deceived tradesmen by substituting empty boxes for others full of money" [Robert Nares, "A Glossary of Words, Phrases, Names, and Allusions," London, 1905]. As a type of toy, it is attested from 1702.