noun. The love child of a dunderhead and a doofus.
Real citation: "Anything that hits it is already a home run. It's not at field level dunderdoof."
(March 27, 2008, SFGate, http://www.sfgate.com/cgi-bin/blogs/sfgate/detail?blogid=22&entry_id=25236)
Made-up citation: "I write all my songs with the growing dunderdoof demographic in mind. How do you think I attract so many comely dunderdoofettes on tour?"