A useless product which is advertised as being needed by everybody, but which in fact no one needs.
2000,David Kumar and Daryl Chubin,Science, Technology, and Society: A Sourcebook on Research and Practice, page 221:
Do You Really, I Mean REALLY, Need a Thneed?
2004,Jonathan Lethem,The Fortress of Solitude, page 361:
I needed orange juice, a toothbrush, a blood transfusion, a Bloody Mary, Abigale Ponders, Leslie Cunningham, a Thneed, someone to watch over me, a miracle every day—anything but a moment of truth between myself and Zelmo Swift.
2012,Shauna Springer,Marriage, for Equals: The Successful Joint (Ad)Ventures of Well-Educated Couples, page 12:
Call now—the remarkable 'thneed' is available only while supplies last...”