Green’s Dictionary of Slang

a genuine (rather than criminal and thus fake) beggar.

1542		Udall (trans.) Erasmus’ Apophthegms (1564) Bk I 59: Not hauyng a raggue to haug about him [...] skorned and laughed at, as Iacke of Bethleem.
1608		Dekker Belman of London C1: Next are Wilde Rogues, [...] then Tom of Bedlams band of madcaps, otherwise called Poore Toms Flocke of Wilde-geese.
1628		R. Speed Counter-Rat F: [A Black Rat] None durst come neere / Like Tom of Bedlam did they fear him.
1635–42		H. Crouch ‘Loves Lunatick’ in Ebsworth Merry Drollery Compleat (1875) 180: Tom Bedlam was a sage to me, / I speak in sober-sadness, / For more strange Visions did I see / Than Tom in all his madness.
1665		Head Eng. Rogue I 156: I have wondred often why Doggs will bark incessantly at the sight of a Tinker, Pedlar, Tom-a-Bedlam.
1674		Head Canting Academy (2nd edn) 54: Abram Men are otherwise called Tom of Bedlams; they are very strangely and antickly garb’d.
1676		‘The Beggars’ Wedding’ in Ebsworth Bagford Ballads (1878) II 874: Then Tom a Bedlam winds his Horn at best.
1683		R. Dixon Canidia i ii: We treat mad-Bedlams, Toms, and Besses, With ceremonies and caresses.
1694		J. Eachard (trans.) Plautus’s Amphitryon IV iii: amp.: Am not I thy Master Amphitryon? mer.: Some Tom a Bedlam I think.
c.1698		B.E. Dict. Canting Crew n.p.: Tom of Bedlam c. the same as Abram-man.
1706		Farquhar Recruiting Officer IV iii: There are several sorts of Toms! Tom o’ Lincoln, Tom-tit, Tom Tell-troth, Tom o’ Bedlam, and Tom Fool.
1719		in D’Urfey Pills to Purge Melancholy IV 189: To find my Tom of Bedlam Ten Thousand Years I’ll Travel.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: mad tom, tom of bedlam otherwise an abram man, a rogue that counterfeits madness, (cant).
1805		Morn, Post 10 May 3/3: See! where Tom o’ Bedlam comes — / Mark his sad, and solemn guise.
1809		G. Andrewes Dict. Sl. and Cant n.p.: Toms of Bedlam fellows who counterfeit madness in the streets, and after beating themselves about, spit out occasionally some blood, in order to convince the too-feeling multitude, that they have injured themselves by violent struggles in their fit; to get the pity of the bye-standers, and obtain relief: they have a small bladder of sheep’s blood in their mouth, and when they think proper they can discharge it; no person telling it from human blood.
1811		Lex. Balatronicum.
1822		R. Nares Gloss. (1888) I 3: abraham-men, or tom of bedlam’s men, or bedlam beggars, A set of vagabonds, who wandered about the country, soon after the dissolution of the religious houses; the provision for the poor in those places being cut off, and no other substituted.
1889		Cornishman 5 Dec. 3/2: It happened one day that a mad Tom of Bedlam came up to Suir Thomas, [...] crying, ‘Leap, Tom — leap’!
1909		J. Ware Passing Eng. of the Victorian Era 247/2: Tom o’ Bedlam (Provincial). A wild, maddish fellow – from the name once given to inoffensive imbeciles who were licensed to go about begging.