to keep something under lock and key
/kˈiːp ˌɛstˌiːˈeɪtʃ ˌʌndɚ lˈɑːk ænd kˈiː/
to keep something under lock and key
01
to keep something private, hidden, or carefully protected
慣用句
例
The manager kept the documents under lock and key.
to keep something private, hidden, or carefully protected
