Entry from OED Online

1958 F. NORMAN Bang to Rights III. 149 ‘Is'nt it a coinsidence that Stanley Golsberg's shop was screwed the other day, and a load of cloth was nicked?’ ‘Alright so how much is the bung?’ Asked Solie. ‘Well lets say a fifty and we did'nt see a thing.’ 1966 J. ASHFORD Consider Evidence vii. 67 What's the matter? Not being offered enough bung?