A cant word among journeymen hatters, signifying the exchanging some of the dearest materials of which a hat is made for others of less value. Hats are composed of the furs and wool of divers animals among which is a small portion of beavers’ fur. Bugging, is stealing the beaver, and substituting in lieu thereof an equal weight of some cheaper ingredient.—Bailiffs who take money to postpone or refrain the serving of a writ, are said to bug the writ.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Bug * Bug-HunterNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes