According to the Register, “The origin of this very rude term is unclear, although it’s thought to have first surfaced on an online football forum. For those of you unfamiliar with the word, it has been summarised as someone ‘possessing properties of striking idiocy.’ “ 

source: Exploring British profanity

Enough said, if you need more please visit my friend Ellen at:

Notes from the U.K.

or get another very specific definition at Urban