Green’s Dictionary of Slang

1. a hoax.

1707		Cibber Double Gallant I i: saun.: I never mind Accounts; I don’t understand ’em. sir sol.: Pray, Sir, what is’t you do understand? saun.: Bite, Bam, and the best of the Lay, old Boy.
1725		New Canting Dict. n.p.: a bam a Sham or Cheat; a knavish Contrivance to amuse or deceive.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.
1762		G. Colman Musical Lady II iii: Why, this is all a bam, madam.
1774		Foote Cozeners in Works (1799) II 192: Pshaw! a bam, Mrs Aircastle; don’t believe it.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: A Bam, a jocular imposition, the same as a humbug.
1809		G. Andrewes Dict. Sl. and Cant.
1815		(con. 18C) W. Scott Guy Mannering (1999) 16: The Laird, whose humble efforts at jocularity were chiefly confined to what were then called bites and bams, since denominated hoaxes and quizzes.
1817		W. Scott Rob Roy (1883) 136: It’s all a bam, ma’am – all a bamboozle and a bite.
1821–6		‘Bill Truck’ Man o’ War’s Man (1843) 115: Oliver [...] knew it was all a bam.
1837		‘The Wide Awake Club’ in Bentley’s Misc. Feb. 214: ‘Well!’ said the president, ‘may I be spiflicated, – ay, and exspiflicated, – if you have not been humbugging us, Pounce, with a pretty piece of bam!’.
1840		T. Haliburton Clockmaker III 168: If it was a bam, there would be no need of advice.
1853		T. Haliburton Sam Slick’s Wise Saws I 33: That was a first-rate bam!
1854		T. Buckley Sydenham Greenfinch 60: [A] really authentic anecdote as a set-off to the outrageous bam his friend had just volunteered.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1866		Wild Boys of London I 280/2: The clerk to Messrs. Bam, Boozle and Bam was really the only visible agent of the company.
1875		E.L. Linton Patricia Kemball III 228: That tale of Gordon Frere was all a bam.

2. a beggar who fakes physical ills.

1891

A. Day Mysterious Beggar 208: ‘Many of these people simulate – pretend to be suffering, when they re not.’ ‘You mean the bams; the scrapers?’.