Meaning of red box | Babel Free

Definitions

1. A phreaking device that generates tones to simulate the insertion of coins into a payphone, thus enabling the user to make illegitimate free calls.
2. A secure briefcase-like box used by ministers in the British government to carry their documents.
   UK
3. A safe located at a nuclear installation containing launch codes.
   US
4. A "tornado watch" notification, indicating that conditions might lead to a tornado though none has yet been sighted.
   US, informal

Examples

“Downing Street has rejected suggestions that David Cameron might have caused a security breach by briefly leaving his official ministerial red box unaccompanied on the table of a train carriage.”

“See also: severe thunderstorm watch”

CEFR level