Definition: In real estate, a mortgage is a loan that allows a borrower to use part of their income or equity as collateral to finance a purchase or construction project. The lender agrees to provide the funds in exchange for a security interest in the property securing the loan. Mortgagers are individuals who are able to borrow money from a lender and then use the proceeds from the sale of their home or other assets to make payments on the mortgage. They typically have the option to pay off the mortgage early,