safe-deposit
Word family
Synonym discussion
Sense: noun/1
All four words describe containers used to protect valuables, but they differ in setting and formality. 'Safe-deposit box' (or the short form 'safe-deposit') refers specifically to a lockable box stored inside a bank vault; it is the most precise term for bank storage. 'Strongbox' is a general term for a portable lockable metal container that can be kept at home or in an office — it need not be in a bank. 'Lockbox' is common in American English and can describe any box with a lock, from a small cash box to a mailbox, and does not imply fireproofing or bank storage. 'Safe' is a heavier, usually non-portable container designed to resist theft and fire, often found in homes or businesses rather than inside a bank vault. In everyday speech, a customer would say 'I put the deed in my safe-deposit box,' whereas a business might use a 'safe' on its premises and a 'strongbox' for cash transport.
Etymology
Formed by combining 'safe' (meaning 'secure, protected from harm', from Old French 'sauf', ultimately from Latin 'salvus') and 'deposit' (meaning 'money or valuables placed for storage', from Latin 'depositum', from 'deponere' meaning 'to lay aside'). The compound 'safe-deposit' originally described a box or vault that provided secure storage for deposited valuables. The variant 'safety deposit box' arose later through analogy with 'safety' as a noun describing the quality of being protected.