Can be subsituted by any string of lyrics from the Arctic Monkeys song of the same name.
"Mardy bum, mate"
2) A fansite dedicated to the above band - www.mardy-bum.com
3) A collection of mardy and bum, someone who moans when they don't get their own way and yet don't do anything for themselves.
**child fails to respond**
mother: ooohhh, you mardybum!
now then, mardybum! - arctic monkeys