black box

1 of 2

noun

1

: a usually complicated electronic device whose internal mechanism is usually hidden from or mysterious to the user

broadly : anything that has mysterious or unknown internal functions or mechanisms

2

: a crashworthy device in aircraft for recording cockpit conversations and flight data

3

: a device in an automobile that records information (such as speed, temperature, or gasoline efficiency) which can be used to monitor vehicle performance or determine a cause in the event of an accident

black box

2 of 2

adjective

: being or containing a warning of a serious or life-threatening side effect (such as stroke or muscle damage) that is highlighted by a black border on a prescription drug's label or accompanying literature

Examples of black box in a Sentence

Noun

The black boxes were recovered from the crash site and provided useful information about the cause of the crash.

Recent Examples on the Web

Noun

Maybe Sam has now left the organization, so Sam’s database is effectively a black box. —Adrian Bridgwater, Forbes.com, 2 Sep. 2025

By illuminating the black box of diffusion models, the new research could have big implications for future AI research—and perhaps even for our understanding of human creativity. —Webb Wright, Wired News, 24 Aug. 2025

Adjective

The black box, or boxed, warning refers to a prominent warning encased in a bold black border in the labeling or pamphlet of some medications. —Kristen Rogers, CNN Money, 4 Sep. 2025

Like OpenAI, the content used to train Midjourney’s technology is a black box, representing an obstacle for some creators who’ve sued AI companies for copyright infringement. —Winston Cho, HollywoodReporter, 4 Sep. 2025

Word History

First Known Use

Noun

circa 1945, in the meaning defined at sense 1

Adjective

1968, in the meaning defined above

Rhymes for black box

• botox
• checkbox
• comox
• cornstalks
• cowpox
• crosswalks
• deadlocks
• detox
• feedstocks
• firebox
• gearbox
• hemlocks

Medical Definition

black box

adjective

: being or containing a warning of a serious or life-threatening side effect (as stroke, muscle damage, or suicidal tendencies) that is highlighted by a black border on a prescription drug's label or accompanying literature

A "black box" warning is the most serious warning placed in the labeling of a prescription medication.

—Johnathan D. Rockoff, The Fort Worth (Texas) Star-Telegram