The Collaborative International Dictionary of English v.0.48:

Flimflam \Flim"flam\, n. [Cf. Flam.]
   A freak; a trick; a lie. --Beau. & Fl.
   [1913 Webster]

WordNet (r) 3.0 (2006):

flimflam
    n 1: a swindle in which you cheat at gambling or persuade a
         person to buy worthless property [syn: bunco, bunco
         game, bunko, bunko game, con, confidence trick,
         confidence game, con game, gyp, hustle, sting,
         flimflam]

Moby Thesaurus II by Grady Ward, 1.0:

206 Moby Thesaurus words for "flimflam":
   balderdash, ballot-box stuffing, balls, baloney, bamboozle,
   bamboozlement, beat, befool, befooling, beguile of, bilk, blague,
   bluffing, bosh, boutade, brainstorm, bull, bullshit, bunco, bunk,
   bunkum, burn, calculated deception, capriccio, caprice,
   cardsharping, cheat, cheating, chicane, chisel, chouse,
   chouse out of, circumvention, claptrap, cock-and-bull story, cog,
   cog the dice, con, conceit, conning, cozen, cozenage, crank, crap,
   craze, crazy idea, crib, crotchet, deceit, deceiving, deception,
   deceptiveness, defraud, defrauding, delusion, delusiveness, diddle,
   diddling, dishonesty, do, do in, do out of, dodge, double-talk,
   drivel, dupery, enmeshment, ensnarement, entanglement, entrapment,
   euchre, exaggeration, eyewash, fad, fairy tale, fake,
   fallaciousness, fallacy, falsehood, falseness, falsity, fancy,
   fantastic notion, fantasy, farfetched story, farrago, fib, fiction,
   finagle, fish story, fishy transaction, flam, fleece, flimflammery,
   fob, fond illusion, fool, fool notion, fooling, fraud, fraudulence,
   fraudulency, freak, freakish inspiration, fudge, gammon,
   gerrymandering, ghost story, gouge, graft, grift, gull, gyp,
   gyp joint, half-truth, hallucination, harebrained idea, have, hoax,
   hocus, hocus-pocus, hogwash, hoke, hokum, hoodwink, hoodwinking,
   hooey, hot air, humbug, humbuggery, humor, illicit business,
   illusion, imposition, imposture, jazz, jiggery-pokery, kidding,
   kink, legal fiction, lie, little white lie, maggot, megrim,
   mendacity, mirage, moonshine, mulct, notion, outwitting, overreach,
   overreaching, pack the deal, passing fancy, phantasm, pigeon,
   pious fiction, practice fraud upon, prevarication, putting on,
   quirk, racket, rook, scam, screw, self-deception, sell,
   sell gold bricks, sham, shave, shortchange, slight stretching,
   snow job, song and dance, spoofery, spoofing, stack the cards,
   stick, sting, story, subterfuge, swindle, swindling, take a dive,
   tale, tall story, tall tale, taradiddle, thimblerig, throw a fight,
   toy, trickiness, tricking, trumped-up story, untruth, vagary,
   victimization, victimize, vision, whim, whim-wham, whimsy,
   white lie, willful misconception, wishful thinking, yarn