Back door, dickhead Share definition Flag A phrase shouted by angry philly teens and disgruntled commuters when the SEPTA bus drive for gets to open the back door of the bus. Bus driver: *opens front door* Disgruntled commuter: “back door, dickheadBus driver: Ma bad Back door, dickhead by Angry_philly_teen October 8, 2019 Get the Back door, dickhead mug.