Alternate definition: to hit, throw, or send flying. To move ungracefully.
This definition has been around for seemingly decades, though nobody is quite sure of it's origin. Some believe it derives from the english word 'blubber', known for being squishy and bouncy, and the word 'bonk'- to hit or tap ungently.
"When Brian told me about that new article, I was totally flubberdonked!"
"She came over to me and flubberdonked the bookright out of my hand."