strongbox
/ˈstrɔːŋbɑːks/
noun
- A strong, usually metal box with a lock, used for storing valuable items such as money, jewelry, or important documents.
- The hotel keeps guests' passports in a strongbox at the front desk.
- The thieves tried to break into the strongbox but couldn't crack the combination lock.
- My grandfather stored his gold coins in an old strongbox hidden under the floorboards.