noun
safe-deposit box
A secure box rented at a bank or similar institution for storing valuables.
銀行の貸金庫に大切な書類を預けている。
I keep important documents in a safe-deposit box at the bank.
Variant with okurigana; also common.
Compound of 貸し (kashi, 'lending') + 金庫 (kinko, 'safe').