What is Bank Walkaway?

Legal Definition
A bank walkaway is a decision by a mortgage lender (a bank) to not foreclose on a defaulted mortgage (when the borrower has ceased to make the payments), or to not complete foreclosure proceedings (to "walk away" from the mortgage). These are sometimes referred to as abandoned foreclosures or stalled foreclosures, though this latter term is also used more broadly when the foreclosure process has stalled for other reasons.

In addition to homes directly owned by a bank, the same phenomenon occurs when the home is part of a mortgage-backed security (MBS), in which case it is the mortgage servicer who has chosen to not foreclose or to cease foreclosure proceedings.

In the United States, bank walkaways have increased in recent years in the wake of the United States housing bubble, and they are also known as red flag homes.
-- Wikipedia