What is Birtwell?
1.
Clumsy, foolish, tendency to pick up copious quantities of nicknames.
See
You've birtwelled it up, haven't you!
2.
someone who eats large amounts of low price, low quality foods.
"My word, you are looking like a bit of a Birtwell"
"I am really hungry, I might do a Birtwell and go to the vending machine"
See