deposit; trust deposit
A sum of money deposited with a third party, often for safekeeping or as a guarantee. Common in legal and financial contexts.
I paid a deposit at the time of the contract.
敷金 is specifically a rental deposit for a property, whereas 預託金 is a broader term for any entrusted deposit.
Compound of 預託 (entrusting, depositing) and 金 (money). The exact historical derivation is uncertain, but the term is a modern financial coinage.