Green’s Dictionary of Slang

1. a tricky or ingenious device, gadget, idea, esp. one adopted for the purpose of attracting attention or publicity.

1893		Electric Rev. 11 Mar. 56/2: [T]he parabola of the dewflicker got jammed hard to starboard, which, of course, caused the flopper to fall down on the mizzen reciprocal eccentricity gimmick.
1911		Sandusky Star Journal (OH) 1 May 5: ’Tis now the agent wanders forth To sell his fruitless trees, / And patent things to mow the lawn, / And dope for honey bees. He’s got a gimmick for the churn, / A patent cellar door, An automatic cistern pump, A salve to heal a sore.
1947		B. Schulberg Harder They Fall (1971) 188: Just one of the little gimmicks I thought up to help the show along.
1955		B. Schulberg On the Waterfront (1964) 51: The short-gang gimmick (hire sixteen men for the work of twenty-two and pad the payroll with ghosts).
1963		M. Spillane Return of the Hood 43: ‘What’s the gimmick,’ he asked.
1979		E. Torres After Hours 34: Saso had all kinds of gimmicks.
1988		D. Woodrell Muscle for the Wing 62: A whole band in casts, why, that’d be a gimmick, but maybe not a good one.

2. (US tramp) the human foot.

1917

Cincinnati Enquirer (OH) 12 May 12/1: ‘I keeps ramblin’ till me gimmicks (feet) felt like a coupla overhet waffle irons’.

3. (US) a foolish person.

1926		in Sat. Eve. Post 23 Oct. 129: There’s an interpreter there, a gimmick with a khaki uniform and a sphinx on his collar [HDAS].
1930		Flynn’s mag. 22 Mar. cited in Partridge DU.
1935		A.J. Pollock Und. Speaks n.p.: Gimmick, a person who has been mulcted by cults, healers, fortune-tellers or mystics.

4. (orig. US) a gadget; spec. a contrivance for dishonestly regulating a gambling game or an article used in a conjuring trick.

1921		N.Y. Times 15 May 71: Being a Possible Questionnaire for Submission to Applicants for the Position of Assistant Stage Doorman [...] What is the starflop? A startrap? A vampire trap? A gimmick?
1927		K. Nicholson Barker 150: Gimmick – A dishonest gaming device.
1933		Ersine Und. and Prison Sl. 40: gimmic, n. Any cheating device.
1949		Monteleone Criminal Sl. (rev. edn).
1953		A.J. Liebling Honest Rainmaker (1991) 77: The old-time bank (faro) play who had to go against the gaff (the gimmick that put him at the dealer’s mercy).
1963		A.S. Fleischman Venetian Blonde (2006) 206: I got into my gimmicks and hurried toward the canals.
1970		‘Red’ Rudensky Gonif 6: Vanelli was a genius at handling the electrical gimmicks, diffusing [sic] the alarms, handling the wiring.
2001		‘Randy Everhard’ Tattoo of a Naked Lady 120: The broken down gimmicks and gizmos.

5. (US Und.) that which helps implement a criminal scheme.

1946		T. Thursday ‘Raw, Medium, and Well Done’ in Blue Ribbon Western June 🌐 ‘What’s the gimmick?’ ‘It’s the old apcray,’ says Horse Tooth.
1952		(con. 1920s) ‘Harry Grey’ Hoods (1953) 68: Now the gimmick in this layout is the freight entrance on the Forty-fourth Street side.

6. (US) affairs, business.

1940

S. Longstreet Decade 146: Five G’s ain’t much. [...] I gotta protect my hoods. The gimmick is worth it, isn’t it? [Ibid.] 317: He’s trigger-nuts and doesn’t like peepers. Just mind your own gimmick.

7. (US) the penis.

1966

L.B. Kenney A Caste of Heroes 19: She shifted my gimmick from side to side, like it was a piece of salami [HDAS].

8. (Aus. Und.) a housebreaking implement.

1950

S.J. Baker in Sun. Herald (Sydney) 8 June 9/4: Among American borrowings recorded in Detective Doyle's list are: [...] ‘gat,’ a gun; ‘gimmick,’ a house breaking instrument [etc].

9. (drugs) usu. in pl., the equipment used for injecting a narcotic drug.

1969		R.R. Lingeman Drugs from A to Z (1970).
1972		E. Grogan Ringolevio 270: He had found an outfit, a set of gimmicks.
2000		N. Tosches Night Train (2001) 253: I think he took too much dope and died. The fact that no gimmick was found means nothing.