The Collaborative International Dictionary of English v.0.48:

Twaddle \Twad"dle\, v. i. & t. [See Twattle.]
   To talk in a weak and silly manner, like one whose faculties
   are decayed; to prate; to prattle. --Stanyhurst.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Twaddle \Twad"dle\, n.
   Silly talk; gabble; fustian.
   [1913 Webster]

         I have put in this chapter on fighting . . . because of
         the cant and twaddle that's talked of boxing and
         fighting with fists now-a-days.          --T. Hughes.
   [1913 Webster]

WordNet (r) 3.0 (2006):

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

Moby Thesaurus II by Grady Ward, 1.0:

106 Moby Thesaurus words for "twaddle":
   absurdity, amphigory, babble, babblement, balderdash, bavardage,
   bibble-babble, blab, blabber, blah-blah, blather, blether,
   blethers, bombast, bosh, bull, bullshit, cackle, caquet,
   caqueterie, chat, chatter, chitter-chatter, clack, claptrap,
   clatter, dither, double-talk, drivel, drool, fiddle-faddle,
   fiddledeedee, flummery, folderol, fudge, fustian, gab, gabble,
   galimatias, gammon, gas, gibber, gibberish, gibble-gabble, go on,
   gobbledygook, gossip, guff, gush, haver, hocus-pocus, hot air,
   humbug, idle talk, jabber, jargon, jaw, malarkey, mere talk,
   mumbo jumbo, narrishkeit, natter, niaiserie, nonsense,
   nonsense talk, pack of nonsense, palaver, patter, piffle,
   poppycock, pour forth, prate, prating, prattle, prittle-prattle,
   ramble on, rant, rattle, rattle on, reel off, rigamarole,
   rigmarole, rodomontade, rubbish, run on, skimble-skamble, spout,
   spout off, stuff and nonsense, stultiloquence, talk away,
   talk nonsense, talk on, talkee-talkee, tittle-tattle, tommyrot,
   trash, trumpery, twattle, twiddle-twaddle, vapor, vaporing, waffle,
   waffling, yak, yakkety-yak