Both me and my friend agree that it means wanking. However, both of our husbands (who have never met, and are from completely different areas of the country) use it to mean skiving off/doing nothing. As an example -
Me- "So what have you done at work today?"
DH- "Not a lot, just tossed it off for most of the day."
Me- "You... wanked, at work, all day?"
DH- "What?! No! I meant that I didn't do any work at work today!"
(Before people pile in and ask why he's lazing about at work, DH only does nothing at work because they don't give him anything to do)
So is it wanking, or skiving?