A sheriff’s officer, who arrests debtors; so called perhaps from following his prey, and being at their bums, or, as the vulgar phrase is, hard at their a-ses. Blackstone says, it is a corruption of bound bailiff, from their being obliged to give bond for their good behaviour.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Bum Trap * Bum BrusherNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes