I have been away from the UK since 1998 and I also had never heard of "clunge" until I saw the Inbetweeners. Something being in the urban dictionary doesn't actually mean its a widely accepted word btw.
I am pretty sure damian could have the word markham in there to mean pussy if he so desired.... if he hasn't already of course.
EDIT: Oh fuck LOL number 4
http://www.urbandictionary.com/define.php?term=markham