tinhorn, adj. — Green’s Dictionary of Slang

tinhorn adj.

[abbr. gambling use tinhorn gambler, a second-rate class of gambler: ‘Chuck-a-luck operators shake their dice in a “small churn-like affair of metal” – hence the expression, “tinhorn gambler”, for the game is rather looked down upon as one for “chubbers” and chuck-a-luck gamblers are never admitted within the aristocratic circle of faro-dealers.’ G.F. Willison, Here They Dug Gold (1931)]

second-rate, inferior, superficially flashy.

1885		Donaldsville Chief (LA) 26 Sept. 1/6: He embellished his elegant flow of language [...] with bright gems from the slang of the profesh and talked about ‘tin-horn’ players.
1897		A.H. Lewis Wolfville 31: Thar’s nothin’ tin-horn about it. It ain’t no skin game neither.
1902		Ade Forty Modern Fables 66: All the Tin-Horn Sports and Shoe-String Gamblers speak of him as their Meal Ticket.
1906		S. Ford Shorty McCabe 35: Say, that was no tinhorn play, was it?
1910		‘O. Henry’ ‘The Gold That Glittered’ in Strictly Business (1915) 31: That [...] rubber-necked tin horn tough.
1920		H.C. Witwer Kid Scanlon 207: You’re a big, tinhorn four-flusher!
1927		T. Thursday ‘A Fray Down South in Dixie’ in Laughter 15 July 🌐 You’re just a couple of tinhorn, street-corner fakers.
1933		J.T. Farrell Gas-House McGinty 14: Say, Mike, is that guy a tin-horn politician?
1935		E. Pound letter 25 Sept. in Paige (1971) 276: The only real one I ever met was O. K., but all American Communists are, as far as I can discover, boneheads, tinhorn repeaters.
1936		(ref. to 1920s) L. Duncan Over the Wall 155: He’s a card-sharp, an all-around tin-horn gambler.
1942		W. Winchell On Broadway 1 May [synd. col.] Tinhorn gamblers who are more concerned about who won what race than who won what battle.
1958		C. Himes Real Cool Killers (1969) 122: Don’t play yourself too big, punk [...] You’re just a cheap, tinhorn punk, yellow to the core.
1978		S. Longstreet Straw Boss (1979) 226: Some tin-horn cheapy tried to push his paper local [...] and got gunned down.
1972		(ref. to 1901) W. Safire New Lang. Politics (2nd edn) 600: ‘Tinhorn politician’ was an epithet coined by William Allen White in an Emporia (Kansas) Gazette editorial on October 25, 1901.
1984		W. Diehl Hooligans (2003) 23: Nance is just a tinhorn shooter.