To put or set down; place. To lay down or leave behind by a natural process: layers of sediment that were deposited on the ocean floor; glaciers that deposited their debris as they melted. To give over or entrust for safekeeping. To put (money) in a bank or financial account. To give as partial payment or security. To become deposited; settle. Something, such as money, that is entrusted for safekeeping, as in a bank. The condition of being deposited: funds on deposit with a broker. A partial or initial payment of a cost or debt: left a $100 deposit toward the purchase of a stereo system. A sum of money given as security for an item acquired for temporary use. A depository. Something deposited, especially by a natural process, as: Geology A concentration of mineral matter or sediment in a layer, vein, or pocket: iron ore deposits; rich deposits of oil and natural gas. Physiology An accumulation of organic or inorganic material, such as a lipid or mineral, in a body tissue, structure, or fluid. A sediment or precipitate that has settled out of a solution. A coating or crust left on a surface, as by evaporation or electrolysis.