Any one of a number of words used to signify a grumbling discontent in instant messaging communications. 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....
When someone younger than yourself talks back to you in an insolentway.
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."