WordNet (r) 3.0 (2006):

malarkey
    n 1: empty rhetoric or insincere or exaggerated talk; "that's a
         lot of wind"; "don't give me any of that jazz" [syn:
         wind, malarkey, malarky, idle words, jazz,
         nothingness]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "malarkey":
   balderdash, baloney, bilge, blah, blah-blah, blatherskite, bop,
   bosh, bull, bullshit, bunk, bunkum, bushwa, crap, flapdoodle, gas,
   guff, gup, hogwash, hokum, hooey, hot air, moonshine, piffle,
   poppycock, rot, scat, shit, tommyrot, tripe, twaddle, wind