Definitions of safe deposit box
a small box that you can rent and use to keep jewellery, documents or other valuables safe, usually in a bank
He lost his savings after termites infested his bank's safe deposit boxes and ate them up.
an internet based or other electronic means of storing electronic documents
The Seller provides the service known as fileTRUST(SM), which is an internet-based safe deposit box for the storage of electronic documents.