Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “under lock and key”

under lock and key

kept safely in a room or container that is locked: I tend to keep medicines under lock and key because of the kids.Putting people in prison
(Definition of under lock and key from the Cambridge Learners Dictionary © Cambridge University Press)
Add Cambridge dictionaries to your browser to your website

Definitions of “under lock and key” in other dictionaries

Word of the Day

bitter

a type of dark brown beer with a bitter taste

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More