This can be used in a couple of different ways, but typically refers to someone who is always hungry or extremely greedy and is always eating. The expression originated with the Royal Navy where the slang name for food is scran. It can also be used to refer to a person who is dirty, untidy, unkempt or of unprepossessing appearance, this too originated with the Royal Navy, perhaps because people who were always eating changed shape so that their uniforms did not fit or were so intent on food that they neglected their appearance.
“If eating was an Olympic sport, you’d be a gold medallist you scran bag!”
“Look at that scruffy sod! What a scran bag!”
“Look at that scruffy sod! What a scran bag!”
by AKACroatalin May 20, 2015