Definition
Safely secured and stored away; protected from theft or damage.
妥善保管
They keep all the important documents under lock and key in a safe.
他们把所有的文件都锁在保险箱里。
To prevent any loss, all valuables were kept under lock and key in the vault.
为了防止任何损失，所有的贵重物品都被锁在保险库里。
The dangerous chemicals in the lab are kept under lock and key in a locked cabinet.
实验室里的危险化学品都被锁在一个上锁的柜子里。
Imprisoned or detained in a place from which escape is impossible, typically a prison.
（尤指罪犯）被监禁或拘留，无法逃脱。
After being sentenced, he was finally under lock and key in prison.
被判刑后，他终于被关在监狱里。
The criminal was kept under lock and key while awaiting trial.
这名罪犯在等待审判期间被关押。
The police ensured all suspects were under lock and key to prevent them from escaping.
警方确保所有嫌疑人都被关押，以防止他们逃跑。