security deposit
From Longman Dictionary of Contemporary Englishsecurity depositseˈcurity deˌposit noun [countable] an amount of money that you give to a landlord before you rent a house or apartment, and that is returned to you after you leave if you have not damaged the propertyExamples from the Corpussecurity deposit• And there usually is a set-up fee and security deposit, plus liability insurance.• You would be required to put down a new security deposit with the new lease drawn up in your name only.