be on the bum(redirected from is on the bum)
be on the bum
To not be working correctly or properly; to be out of order; broken. My car has been on the bum ever since I let my brother borrow it for the weekend. I think our washing machine is on the bum—these clothes are all sopping wet and don't smell clean!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.