The Collaborative International Dictionary of English v.0.48:

baloney \ba*lo"ney\, n.
   1. [Believed to be derived form balogna, but perhaps also
      influenced by blarney.] nonsense; foolishness; bunk; --
      also used as an interjection. [Also spelled boloney.]
      [slang]
      [PJC]

            No matter how thin you slice it, it's still baloney!
                                                  --Al Smith.
      [PJC]

   2. informal variant of bologna[2], for bologna sausage.
      [informal]
      [PJC]

WordNet (r) 3.0 (2006):

boloney
    n 1: pretentious or silly talk or writing [syn: baloney,
         boloney, bilgewater, bosh, drool, humbug,
         taradiddle, tarradiddle, tommyrot, tosh, twaddle]