A term used by a tradesman originally believed to be separated by a semicolon, i.e...
BAD part; ORDER a new one
The common adjective is an all-encompassing term used to describe something that is broken, while at the same time, being as nondescript as possible to avoid excessive work.
Repair Order: "engine is b/o"
Rookie: "the engine smells?"
Veteran: "No, it's broken"
Rookie: "What do you mean broken? What kind of broken? Does it have a miss? does it leak? Is it broken in two?"
Veteran: "Dunno yet, lets go inspect it."
Rookie: "Who wrote this up? Didn't the inspector already inspect it in the first place?!"
Rookie: "Lazy swing-shifter"