The Collaborative International Dictionary of English v.0.48:

Clatter \Clat"ter\, v. i. [imp. & p. p. Clattered; p. pr. &
   vb. n. Clattering.] [AS. cla?rung a rattle, akin to D.
   klateren to rattle. Cf. Clack.]
   1. To make a rattling sound by striking hard bodies together;
      to make a succession of abrupt, rattling sounds.
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            Clattering loud with iron clank.      --Longfellow.
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   2. To talk fast and noisily; to rattle with the tongue.
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            I see thou dost but clatter.          --Spenser.
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The Collaborative International Dictionary of English v.0.48:

Clatter \Clat"ter\, v. t.
   To make a rattling noise with.
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         You clatter still your brazen kettle.    --Swift.
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The Collaborative International Dictionary of English v.0.48:

Clatter \Clat"ter\, n.
   1. A rattling noise, esp. that made by the collision of hard
      bodies; also, any loud, abrupt sound; a repetition of
      abrupt sounds.
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            The goose let fall a golden egg
            With cackle and with clatter.         --Tennyson.
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   2. Commotion; disturbance. "Those mighty feats which made
      such a clatter in story." --Barrow.
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   3. Rapid, noisy talk; babble; chatter. "Hold still thy
      clatter." --Towneley Myst. (15 th Cent. ).
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            Throw by your clatter
            And handle the matter.                --B. Jonson
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WordNet (r) 3.0 (2006):

clatter
    n 1: a rattling noise (often produced by rapid movement); "the
         shutters clattered against the house"; "the clatter of iron
         wheels on cobblestones"
    v 1: make a rattling sound; "clattering dishes" [syn: clatter,
         clack, brattle]

Moby Thesaurus II by Grady Ward, 1.0:

126 Moby Thesaurus words for "clatter":
   Bedlam let loose, babble, babblement, bavardage, bedlam,
   bibble-babble, bicker, blab, blabber, blah-blah, blast, blather,
   blether, blethers, bobbery, brattle, brawl, brouhaha, cackle,
   caquet, caqueterie, charivari, chat, chatter, chirm,
   chitter-chatter, clack, clacket, clamor, clangor, clap,
   clatter about, clitter, clitterclatter, clunter, commotion, din,
   discord, dither, donnybrook, drunken brawl, dustup, flap, fracas,
   free-for-all, gab, gabble, gas, gibber, gibble-gabble, go on,
   gossip, guff, gush, hassle, haver, hell broke loose, hot air, howl,
   hubbub, hue and cry, hullabaloo, hurly-burly, idle talk, jabber,
   jangle, jaw, loud noise, mere talk, natter, noise,
   noise and shouting, nonsense talk, outcry, palaver, pandemonium,
   patter, pother, pour forth, prate, prating, prattle,
   prittle-prattle, racket, ramble on, rattle, rattle around,
   rattle on, rattletybang, rattling, reel off, retail gossip,
   rhubarb, roar, row, ruckle, ruckus, ruction, rumble, rumpus,
   run on, shatter, shindy, shivaree, spout, spout off, talk,
   talk away, talk nonsense, talk on, talkee-talkee, tattle,
   tell idle tales, thunder, thunderclap, tintamarre, tittle-tattle,
   to-do, tumult, turmoil, twaddle, twattle, uproar, waffle, yak,
   yakkety-yak