security deposit پول پیش (هنگام اجاره کردن)

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 property  

Do you require a security deposit? 

That will come out of your security deposit. (come out of = کسر شدن از)

The security deposit is a month-and-a-half's rent. 

We require the first and last months' rent and a security deposit up front. (up front = از پیش)

The landlord demanded one month security deposit for rent, another for damage to the apartment, and one month rent in advance.
Landlords will often want a security deposit and two months rent in advance.