Mortgage

Definition of Mortgage:
A temporary and conditional pledge of property to a creditor as security for the performance of an obligation or the repayment of a debt. In other words, using a home as property to secure a loan. Often used to purchase the home.
There are a million articles waiting to happen on this topic. Mortgage is so broad a term that it could be included in a personal finance site as well as real estate and home mortgage sites.

Some good article titles:
Things to Look Out for When Shopping for a Mortgage
Mortgage Do's and Don'ts
Using a Mortgage to Pay Off Credit Card Debt
Home Mortgages for People with Bad Credit
Using a Second Mortgage to Finance College
Finding a Good Home Mortgage Rate

We also need plenty of sections explaining what a mortgage is and how it compares to other types of loans, how much will you need for a down payment, home mortgage calculators and so forth.
This is a very broad topic so you will really need to do something special to stand out enough to sell your work.