under lock and key
被嚴密保管,禁止訪問或觸摸
口語·強調(diào)安全保管或限制訪問
英文釋義
to be securely locked or closely guarded; to be kept in a safe or secure place
例句
Mom keeps all the Christmas presents under lock and key so we can't peek.
典故來源
源于中世紀,貴重物品被鎖在箱子或房間里,鑰匙由專人保管,確保安全。