Never heard the term either. When I was a ramp agent, I once caught a bowser driver deliberately entering an additional 100 kg on the refuelling panel. He told me he was doing so because on the A320 there was a known discrepancy between the fuel quantity indications on the refuelling panel and on the flight deck. Since the crew didn't seem to bother, I never thought about it again, and I never saw any bowser driver doing it again.