deposit /dɪˈpɒzɪt/ noun [C]
BUYING › a payment that you make immediately when you decide to buy something, as proof that you will really buy it: They've put down a deposit on a house.
BANK › an amount of money that you pay into a bank: to make a deposit
SUBSTANCE › a layer of a substance that has developed from a natural or chemical process: deposits of iron ore
RENT › an amount of money that you pay when you rent something, and that is given back to you when you return it without any damage