depositDefinition and Meaning of a Deposit. Simply put, a deposit is a sum of money that an individual or entity places into a bank account or financial institution. This amount can be in the form of cash, check, or electronicDefine deposit. deposit synonyms, deposit pronunciation, deposit translation, English dictionary definition of deposit. v. de·pos·it·ed , de·pos·it·ing , de·pos·its v. tr. 1. To put or set down;