jack-in-the-box

American  

[jak-in-thuh-boks] / ˈdʒæk ɪn ðəˌbɒks /

Or jack-in-a-box

noun

plural

jack-in-the-boxes

1. a toy consisting of a box from which an enclosed figure springs up when the lid is opened.

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jack-in-the-box British  

noun

1. a toy consisting of a figure on a compressed spring in a box, which springs out when the lid is opened

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Etymology

Origin of jack-in-the-box

First recorded in 1545–55

Example Sentences

They discovered that the TCR behaves like a jack-in-the-box, staying compact until it encounters an antigen or another suspicious particle, at which point it rapidly opens.

From Science Daily • Dec. 18, 2025

Australia left the UK last summer with their baggy greens spinning, and India are now twisting the handle of the jack-in-the-box, terrified of when it will burst open.

From BBC • Feb. 6, 2024

He demonstrates with a broad smile, his sinewy frame repeatedly squatting, then snapping back up, like a peppy jack-in-the-box.

From Los Angeles Times • Jan. 24, 2024

She transformed a set of headphones into a jack-in-the-box figure wearing headphones while playing a guitar.

From New York Times • Feb. 23, 2023

To prove his point, he popped his head back inside the rock and then back out again like some kind of deranged jack-in-the-box.

From "Glitch" by Laura Martin