The Collaborative International Dictionary of English v.0.48:

Piffle \Pif"fle\, n.
   Act of piffling; trifling talk or action; piddling; twaddle.
   [Dial. or Slang] "Futile piffle." --Kipling.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Piffle \Pif"fle\, v. i. [imp. & p. p. Piffled; p. pr. & vb. n.
   Piffling.]
   To be sequeamish or delicate; hence, to act or talk
   triflingly or ineffectively; to talk nonsense or about
   trivial matters; to twaddle; piddle. [Dial. or Slang]

   Syn: chatter, palaver, prate, tittle-tattle, twaddle, clack,
        maunder, prattle, gibber, tattle, blabber, gabble.
        [Webster 1913 Suppl. + WordNet 1.5]

   2. To act in a trivial or ineffective way.
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

piffle
    n 1: trivial nonsense [syn: balderdash, fiddle-faddle,
         piffle]
    v 1: speak (about unimportant matters) rapidly and incessantly
         [syn: chatter, piffle, palaver, prate, tittle-
         tattle, twaddle, clack, maunder, prattle, blab,
         gibber, tattle, blabber, gabble]
    2: act in a trivial or ineffective way

Moby Thesaurus II by Grady Ward, 1.0:

47 Moby Thesaurus words for "piffle":
   babble, balderdash, baloney, bilge, blabber, blah, blah-blah,
   blather, blatherskite, bop, bosh, bull, bullshit, bunk, bunkum,
   crap, drivel, drool, flapdoodle, gabble, gas, gibber,
   gibble-gabble, guff, gup, hogwash, hokum, hooey, hot air, jabber,
   malarkey, moonshine, poppycock, prate, prattle, rattle, rot, scat,
   shit, talk nonsense, tommyrot, tripe, twaddle, twattle, vapor,
   waffle, wind