As uttered by Rowan Atkinson in the film 'Johnny English' after accidentally injecting himself with a paralysing serum. A sound made in response to total incomprehension to a statement or series of statements or questions directed at that person immediately beforehand.
After a complicated lecture by a physics teacher, the question is asked "What is x?" The response to which is "Phlabb?"
by Mr Quote Sarcastic Unquote December 27, 2008