Green’s Dictionary of Slang

chats n.2

also chatts, chits
[SE chattels, moveable property, typically livestock, ‘lice being the chief livestock of beggars, gypsies, and the rest of the canting crew’ (Grose, 1785)]

1. (UK Und.) lice; thus chat parade, a delousing session.

[UK]B.E. Dict. Canting Crew.
[UK]A. Smith Lives of Most Notorious Highway-men, etc. (1926) 204: Chats, lice. Squeeze the chats, i.e., crack or kill those vermin.
[UK]New Canting Dict.
[UK]Bailey Universal Etym. Eng. Dict.
[UK]B.M. Carew Life and Adventures.
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: Chatts, lice, (cant) perhaps an abbreviation of chattels, lice being the chief live stock or chattels of beggars, gypsies, and the rest of the canting crew.
[UK]Vaux Vocab. of the Flash Lang.
[UK]‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 24: Chatts — i.e. Chattels, abbreviated — Lice.
[UK]Swell’s Night Guide 65: You staggs my queer togs, and thinks I’m chatty; but Lord love you! I never had a chat in my mortal days. [Ibid.] 72: I’ve copped some nob-rangers, and I arnt got no chat-rake; so I shall snuff ’em out.
[UK]Kendal Mercury 17 Apr. 6/1: Blow me [...] if that ken of Beggar-me-Out’s vasn’t crammed full of chats (lice) and hoppers (flies).
[US]Matsell Vocabulum.
[UK]W.H. Smyth Sailor’s Word-Bk (1991) 181: Chats. Lice. Also lazy fellows.
[UK]Hotten Sl. Dict. 97: CHATTS, lice.
[UK]Dly Gaz. for Middlesborough 6 Nov. 3/4: Twenty-seven of us in one room, most of us dirty [...] Then the ‘flats’ and ‘chits’ [...] Suffice it to say that they were at (sic) work, and I was awake the whole night through.
[US]Rising Sun 25 Dec. 8/2: Why waste all that ration jam [...] add a little fat— / And we could use it well, / In killing off the chat.
[UK]A. Wright diary 15 Aug. in Muddy France (1988) 12: Had a lengthy ‘chat parade’, and a bath.
[Aus]Aussie (France) 11 Feb. 11/1: When in the trenches one gets used to chats, as you blokes know, and looks upon them the same way that a dog regards fleas. They keep a fellow from worrying about his other worries.
[UK](con. WWI) E. Lynch Somme Mud 51: Dark and I get out of our underpants and pull them on again, inside out, to trick the chats [...] We chance the chats about our upper regions.
[UK](con. WWI) Fraser & Gibbons Soldier and Sailor Words 52: Chat, A: Vermin, in particular a louse.
[UK]E. Blair letter 4 Sept. in Complete Works X (1998) 228: As to new words, here are some [...] Chat = a louse.
[Aus]Western Mail (Perth) 11 June 2/5: There was a bottle of dope in the corner that they used for chats [...] Three or four others took off their flannels and strides and sprinkled some in the seams.
[Aus]Western Mail (Perth) 30 May 2/3: Chats soon became too common to take notice of.
[Aus] ‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxiii 4/3: chat: A prison bed-bug.
[Aus]Adamson & Hanford Zimmer’s Essay 99: Orwell gives ‘chat’ as a term for ‘louse’ [...] In New South Wales prison argot, it means both ‘louse’ and a certain type of prisoner.
[Aus]G. Seal Lingo 59: Many of these terms are still used. On Gallipoli the Anzacs soon made the acquaintance of body lice, or chats, a term also common in US folk speech.
[UK]J. Meades Empty Wigs (t/s) 618: ‘Diabolical itchy like chats all over you it were. Worse than these patches’.

2. (Aus. teen) as defined by a sharpie n.2 gang, a victim, a pariah.

[Aus](con. 1960s-70s) T. Taylor Top Fellas 21/1: The lowest of the low were called ‘Chats’. [...] In sharp lingo it meant a paraiah, in for a hiding.

In compounds