Green’s Dictionary of Slang

1. (US) a flatterer.

1899–1900

C.L. Cullen Tales of the Ex-Tanks 139: He was a pretty good con man, and he nailed me for that positively last and final appearance.

2. (orig. US, also con boy, con guy, con player, con-woman) a confidence trickster [later use is SE].

1889		Portland Mercury 29 June 1/7: It does not take an unsophisticated countryman to get swindled by the ‘con man’ [DA].
1893		J. Hawthorne Confessions of Convict 143: She’s one of the best ‘con-women’ in the world.
1902		E. Townsend Chimmie Fadden and Mr Paul 95: De con man and come-on.
1905		F. Hutchison Philosophy of Johnny the Gent 79: ‘[H]e couldn’t tell a con guy from a hodcarrier’.
1916		J. Lait ‘Charlie the Wolf’ in Beef, Iron and Wine (1917) 72: [He is] only a con-man what couldn’t lick nobody.
1925		D. Hammett ‘Dead Yellow Women’ Story Omnibus (1966) 160: In 1908 Conyers appeared on the Pacific coast [...] in company with a con man known as ‘Duster’ Hughes.
1926		N. Lucas London and its Criminals 32: Madge Carson, one of the smartest ‘con’ women (confidence tricksters) in England.
1932		Sun. Mail (Brisbane) 13 Nov. 20/8: The men who worry the police most are the ‘whizz’ or ‘con.’ men.
1936		J. Curtis Gilt Kid 50: Not a bad con-man in her own way when he came to weigh it up. She had let him make the running, and suggest the dough himself.
1942		‘Digg Mee’ ‘Observation Post’ in N.Y. Age 29 Aug. 9/6: The ‘con-man’ and the hustlers are fading fast away [...] in search of fatter prey.
1944		News of the World 11 June 7: An expert ‘con’ man, with a criminal career, under seven aliases, dating back to 1905, has returned to penal servitude.
1953		R. Prather ‘Double Take’ in Best of Manhunt (2019) [ebook] Confidence men are psychologists with diplomas from sad people: the suckers, the marks, that the con-boys have taken.
1953		I. Hamilton Till Human Voices Wake Us 156: There was a Con-man in the hut next to Phil.
1957		Kerouac On The Road (1972) 10: Though he was a con-man, he was only conning because he wanted so much to live.
1957		C. Himes Imabelle 40: There was a con man called Morgan in my place last night.
1960		(con. 1926) J. Havoc Early Havoc 72: That was my first brush with a real con woman.
1965		C. Himes Rage in Harlem (1969) 42: [as 1957].
1969		‘Iceberg Slim’ Pimp 34: He entreats the con player to take him there, not just direct him.
1972		P. Fordham Inside the Und. 92: Con-men are not much liked in the underworld.
1985		N. Pileggi Wiseguy (2001) 191: The body of a forty-two-year-old hustler and con man.
1994		Indep. Mag. 6 Aug. 6: Having been bamboozled by a con-man on his doorstep.
2004		Mad mag. Jan. 10: I hate street hustlers, pushers [and] con men.
2010		A. Steinberg Running the Books 36: Jacob was a con man who spent most of his life on the lam.
2011		G. Phillips ‘Slicers’ Serenade of Steel’ in Pulp Ink [ebook] Sally Sincyr, a con woman who specialized in the grieving niece bit.
2016		Rolling Stone 14 Oct. 🌐 Egged on to a doomed rebellion by a third-rate con man who wilted under pressure.
2020		G. Disher Consolation 302: ‘Enter a pair of Irish conmen’.

3. attrib. use of sense 2.

1951

Kerouac On the Road (The Orig. Scroll) (2007) 357: A rangy bashful shock-haired Denver boy with a big conman smile.

4. (US) a former convict.

1930

‘Dean Stiff’ Milk and Honey Route 203: Con man [...] ex-convict.