1. The total amount of money lent to a borrower by a money-lending organization, with some of the borrower’s property being given as security.
2. Historically, when the oldest son of a nobleman needed large sums of money which his father refused to give him, he often turned to borrowing.

In arranging the loan, he would gage or “pledge” to repay the debt when his father died (at which time the son expected to receive his inheritance).

So it is that mortgage originally meant a pledge to repay upon the death of one’s father. Now the word is used when someone pledges property as a guarantee; such as, a house, to a creditor as security or a guarantee for the repayment of a loan or other debt; as shown in the illustration below.

A class of property that is used by borrowers who have low credit ratings: Borrowers who have subprime mortgages generally do not qualify for loans with lower rates because they have "damaged credit" or no credit history, and so they are considered untrustworthy by lending institutions.

Since the default risk for poor credit borrowers is greater than for other kinds of borrowers, lenders will normally charge a higher interest rate for subprime mortgages.