Green’s Dictionary of Slang

1. (also flam-blam) nonsensical, insubstantial, esp. as flim-flam tale, etc.

1598		Florio Worlde of wordes n.p.: Cantilena, a ballad, a tale, a report, a flim-flam discourse [...] Cipollata, a flim-flam tale, a tittle tattle, a skoulding, a rayling.
1613		Florio [trans.]Montaigne Essays 66: Idiots and foolish people, who [...] onely ammuse themselves to know the succession of Kings, the establishing and declination of estates, and such like trash of flim-flam tales.
1623		M. Aleman [trans.] Guzman de Alfarache 16: Nouelties please all, especially women, who are louers of flim-flam tales, and for the receiuing and returning of newes.
1638		A. Tatius [trans.] The loves of Clitophon and Leucippe 213: Againe he tels you a flim flam tale of a fellow prisoner of his.
1648		A. Babington An answer to a discourse 93: [He] makes him tell at first a flimflam tale, and then promise more particulars in a short time, that thereby more time might be gained for him to stay in Town without suspition.
1653		Reasons why the supreme authority [...] is not in the Parliament 19: Subtilty [...] in sub-distinguishing of abstracted flimflam-notions, help very much to cry up men to the title of good Scholars, in the estimation of frothy Wits.
1664		C. Cotton Virgil Travestie (1765) Bk I 32: And fobb’d Queen Dido off / [...] / By telling her a Flim Flam Prattle.
1676		T. Mace Musick's monument 43: [I] will never more give Credit to that Flim-Flam-Ignorant saying of the Vulgar.
1683		Fifteen Real Comforts of Matrimony 57: Why then did the woman […] endeavour to blind him with her flim-flam-stories.
1691		The blatant beast muzzl’d 142: Talk serves him for well-grounded Truth, meer Pretences for Proofs, and flimflam Stories for clear Evidences.
1700		Scarron [trans.] Works 193: [H]e returned to his Drunkards, amusing them with flim flam Stories.
1875		Junction City (KS) 5 Aug. 1/8: ‘Oh yes, gimme ten cents worth of hair-pins [...] The gal is always wanting some flim-flam thing’ .
1888		Huddersfield Chron. 14 Aug. 4/3: It is not really a system of elementary education at all, but a system largely taken up with flim-flam instruction.
1890		Manchester Courier 26 Apr. 14/6: It’s wonderful what flim-flam noshins they do get up to nowadays.
1898		H. Macfall Wooings of Jezebel Pettyfer 171: All t’udder talk are flam-blam foolishness.
1904		E.W. Townsend ‘Chimmie Fadden’ 25 Dec. [synd. col.] ‘It’s philos’phy,’ he says. ‘What kind of a flim-flam game is dat?’ I says.

2. pointless, undemanding, meaningless.

1581

M. Luther [trans.] A commentarie [...] vppon the twoo Epistles generall of Sainct Peter 76: [T]hose flim-flam toyes, and friuolous deuises.

3. tricky, cheating.

1902		C.L. Cullen More Ex-Tank Tales 100: Don’t youse try none o’ dat flim-flam woik wit’ me.
1920		Sun. Post (Dundee) 4 Apr. 3/5: The nation got tired of that sort flim-flam game.
1940		E. Curry Hysterical Hist. of Aus. 40: A pretty dod gasted ding-whanged, flim-flammin set of thieves, rogues and vagabones.
1956		H. Gold Man Who Was Not With It (1965) 303: Past the tall flimflam captains’ houses with the wooden roosts at the top.