under lock and key

under lock and key

Securely hidden away. I keep my grandmother's secret recipe under lock and key so that no one can steal it.
See also: and, key, lock
Farlex Dictionary of Idioms.

under lock and key

Securely locked up, as in He keeps the wine under lock and key. [First half of 1500s]
See also: and, key, lock
The American Heritage® Dictionary of Idioms by Christine Ammer.

under lock and key

securely locked up.
See also: and, key, lock
Farlex Partner Idioms Dictionary

under ˌlock and ˈkey

locked up in prison, in a safe, etc: The escaped prisoners are now safely under lock and key. The exam papers must be kept under lock and key until half an hour before the exam.
See also: and, key, lock
Farlex Partner Idioms Dictionary

under lock and key

Securely locked up.
See also: and, key, lock
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • off key
  • off-key
  • key in
  • hot wire
  • wired
  • wiring
  • transpose (something) from (something) (in)to (something)
  • high-key
  • key off
  • transpose (something) to (something)