jingle mail
n.— «Kosciuszko said the mortgage insurance industry coined the term “jingle mail” because homeowners whose mortgages were worth far more than their homes literally mailed their house keys in to lenders.» —“Haunted by debt” by Pamela Yip Houston Chronicle (1) Nov. 1, 1992. (source: Double-Tongued Dictionary)
Further reading
What’s the common bond that links the names Vanessa, Cedric, and Pamela? They’re all names coined by famous authors. Vanessa was invented by Jonathan Swift as a pet name for his lover Esther Van Homrigh.The 16th-century poetSir Phillip Sidney coined...
While reading Dean Koontz’s book The House at the End of the World (Bookshop|Amazon), a listener in Ramona, California, encountered the perfect word for the walks he takes with his dog. He now refers to such an excursion as a sniffari. This is part...