English Dictionary

under lock and key

prep_phrase

(US, UK, idiomatic) imprisoned with little or no chance of escape; locked up. / (US, UK, idiomatic) safely guarded; locked away.

The valuable jewelry is kept under lock and key.

意味（1）

(US, UK, idiomatic) imprisoned with little or no chance of escape; locked up.

If it was him we can have him under lock and key in 24 hours.

意味（2）

(US, UK, idiomatic) safely guarded; locked away.

It is the policy of the organization to keep unused check supplies safeguarded under lock and key.