black box

American  

noun

1. any unit that forms part of an electronic circuit and that has its function, but not its components, specified.

2. any comparatively small, usually black, box containing a secret, mysterious, or complex mechanical or electronic device.

3. Aeronautics. an electronic device, such as a flight recorder, that can be removed from an aircraft as a single package.

4. Automotive. a device in an electronic ignition system that generates electrical pulses.

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black box British  

noun

1. a self-contained unit in an electronic or computer system whose circuitry need not be known to understand its function

2. an informal name for flight recorder

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black box Cultural  

1. A crash-resistant steel container that holds instruments that record performance data in airplanes. The data are used to analyze the causes of accidents.

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Etymology

Origin of black box

First recorded in 1940–45

Example Sentences

It took almost two years and multiple search campaigns to find the wreckage and the plane’s black box recorders.

From The Wall Street Journal • May 21, 2026

He added that black box was about "keeping prices down and keeping people safe" and its data had also found younger drivers to be the highest risk.

From BBC • Apr. 1, 2026

We don’t know what’s happening inside the black box.

From The Wall Street Journal • Mar. 20, 2026

But her probe would be a black box that she could slow-walk indefinitely.

From Slate • Mar. 6, 2026

He would conquer all, even the black box.

From "The Chocolate War" by Robert Cormier