Any one of a number of words used to signify a grumbling discontent in instant messagingcommunications. The word is made up of letters closely spaced on the querty keyboard.
I'm going out to have my smoke seeing as I am unable to eat more berties, .grumble .........grumble......sassafrassa....
After overhearing the childs tirade to her parents the grandmother intervened by saying, " Hush up you little sassbacker this is a perfect example of spare the rod, spoil the child."