Green’s Dictionary of Slang

1. (orig. US) to act as a frontman, either in a casino, where one is a house player, or in ext. senses.

1914		Jackson & Hellyer Vocab. Criminal Sl. 75: To ‘shill’ is to act in the capacity of a hired criminal.
1916		J. Lait ‘Omaha Slim’ in Beef, Iron and Wine (1917) 104: Omaha Slim, having shilled a night owl for a dime, repaired him to the lodging-house of his choice.
c.1930		(ref. to late 19C) N. Kimball Amer. Madam (1981) 207: I soon got the hang of it after Solly shilled a few games and won himself some of the crumby trash. Then I said to the pack of people [...] ‘You all saw the gentleman carry off his valuable and wonderful prizes. You can do it. Step up.’.
1949		F. Brown Dead Ringer 143: She was going to shill on Walter’s wheel for awhile.
1956		I. Fleming Diamonds Are Forever (1958) 72: The big entertainers shilled for the games which were not financed to be beaten.
1960		C. Himes Big Gold Dream 136: All you’re doing is shilling for Clay, the undertaker.
1963		M. Spillane Return of the Hood 48: Right now that Federal agency you shilled for a couple of years ago is breathing down your neck.
1969		B. Jackson Thief’s Primer 74: I started out shilling and I became a crap dealer.
1976		R. Sabbag Snowblind (1978) 116: When he was deep in the hole he would shill at Adrian’s casino on the park.
1986		C. Hiaasen Tourist Season (1987) 316: The most innocuous of TV celebrities, delighted to shill for the tourist board in exchange for comped rooms at the Fontainebleau.
2002		Guardian G2 26 Mar. 11: Woody Allen turned up to shill for New York’s film industry.
2015		P. Beatty Sellout (2016) 275: A giant photo of Michael Jordan shilling for Nike.

2. to act as an ‘agent’, directing clients to a prostitute; thus shilling adj.

1951		N.Y. Age 29 Dec. 4/1: This was final degredation; commercially advertising and ‘shilling’ for an established ‘medicine mill’ from the pulpit.
1967		in S. Harris Hellhole 86: She learned about madams and shilling cabdrivers and bartenders.
2010		(con. 1973) C. Stella Johnny Porno 92: This one passed me a name the other day, one of the girls she shills for.

3. (US black) to trick.

1957

D. Burley N.Y. Amsterdam News 8 June 14: Tall Paul [...] was trying to shill Philadelphia Lil out of a buck.