The Collaborative International Dictionary of English v.0.48:

Rattle \Rat"tle\, n.
   1. A rapid succession of sharp, clattering sounds; as, the
      rattle of a drum. --Prior.
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   2. Noisy, rapid talk.
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            All this ado about the golden age is but an empty
            rattle and frivolous conceit.         --Hakewill.
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   3. An instrument with which a rattling sound is made;
      especially, a child's toy that rattles when shaken.
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            The rattles of Isis and the cymbals of Brasilea
            nearly enough resemble each other.    --Sir W.
                                                  Raleigh.
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            Pleased with a rattle, tickled with a straw. --Pope.
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   4. A noisy, senseless talker; a jabberer.
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            It may seem strange that a man who wrote with so
            much perspicuity, vivacity, and grace, should have
            been, whenever he took a part in conversation, an
            empty, noisy, blundering rattle.      --Macaulay.
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   5. A scolding; a sharp rebuke. [Obs.] --Heylin.
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   6. (Zool.) Any organ of an animal having a structure adapted
      to produce a rattling sound.
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   Note: The rattle of a rattlesnake is composed of the hardened
         terminal scales, loosened in succession, but not cast
         off, and so modified in form as to make a series of
         loose, hollow joints.
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   7. The noise in the throat produced by the air in passing
      through mucus which the lungs are unable to expel; --
      chiefly observable at the approach of death, when it is
      called the death rattle. See R[^a]le.
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   To spring a rattle, to cause it to sound.

   Yellow rattle (Bot.), a yellow-flowered herb (Rhinanthus
      Crista-galli), the ripe seeds of which rattle in the
      inflated calyx.
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The Collaborative International Dictionary of English v.0.48:

Rattle \Rat"tle\ (r[a^]t"t'l), v. i. [imp. & p. p. Rattled
   (-t'ld); p. pr. & vb. n. Rattling (-tl[i^]ng).] [Akin to D.
   ratelen, G. rasseln, AS. hr[ae]tele a rattle, in
   hr[ae]telwyrt rattlewort; cf. Gr. kradai`nein to swing, wave.
   Cf. Rail a bird.]
   1. To make a quick succession of sharp, inharmonious noises,
      as by the collision of hard and not very sonorous bodies
      shaken together; to clatter.
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            And the rude hail in rattling tempest forms.
                                                  --Addison.
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            'T was but the wind,
            Or the car rattling o'er the stony street. --Byron.
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   2. To drive or ride briskly, so as to make a clattering; as,
      we rattled along for a couple of miles. [Colloq.]
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   3. To make a clatter with the voice; to talk rapidly and
      idly; to clatter; -- with on or away; as, she rattled on
      for an hour. [Colloq.]
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The Collaborative International Dictionary of English v.0.48:

Rattle \Rat"tle\ (r[a^]t"t'l), v. t.
   1. To cause to make a rattling or clattering sound; as, to
      rattle a chain.
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   2. To assail, annoy, or stun with a rattling noise.
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            Sound but another [drum], and another shall
            As loud as thine rattle the welkin's ear. --Shak.
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   3. Hence, to disconcert; to confuse; as, to rattle one's
      judgment; to rattle a player in a game. [Colloq.]
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   4. To scold; to rail at. --L'Estrange.
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   To rattle off.
      (a) To tell glibly or noisily; as, to rattle off a story.
      (b) To rail at; to scold. "She would sometimes rattle off
          her servants sharply." --Arbuthnot.
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WordNet (r) 3.0 (2006):

rattle
    n 1: a rapid series of short loud sounds (as might be heard with
         a stethoscope in some types of respiratory disorders); "the
         death rattle" [syn: rattle, rattling, rale]
    2: a baby's toy that makes percussive noises when shaken
    3: loosely connected horny sections at the end of a
       rattlesnake's tail
    v 1: make short successive sounds
    2: shake and cause to make a rattling noise

Moby Thesaurus II by Grady Ward, 1.0:

333 Moby Thesaurus words for "rattle":
   Bedlam let loose, Klaxon, abash, abate, addle, addle the wits,
   agitate, agreeable rattle, assault, attenuate, babble, babbler,
   ball up, battery, bear, bear upon, becloud, bedazzle, bedlam,
   befuddle, bells, bewilder, bicker, big talker, blab, blabber,
   blabberer, blast, blather, blatherer, blether, blunt, bobbery,
   boiler factory, boiler room, bones, boost, bother, bounce, brattle,
   brawl, brouhaha, buck, bug, bull, bull-roarer, bulldoze, bullshit,
   bump, bump against, bunt, butt, butt against, cackle, call off,
   castanets, catcall, celesta, charivari, chat, chatter, chatterbox,
   chatterer, cherry bomb, chime, chimes, chirm, clack, clacker,
   clacket, clamor, clangor, clap, clapper, clappers, clatter,
   clatter about, clitter, clitterclatter, cloud, clunter, commotion,
   confound, confuse, cracker, crackle, crackling, cram, cramp,
   crash cymbal, cricket, cripple, crowd, cymbals, damp, dampen, daze,
   dazzle, deaden, debilitate, devitalize, dig, din, discombobulate,
   discomfit, discompose, disconcert, discord, discountenance,
   disorganize, disorient, disquiet, distract, disturb, dither,
   donnybrook, drive, drivel, drool, drunken brawl, dull, dustup,
   elbow, electrify, embarrass, enervate, enfeeble, entangle,
   enumerate, eviscerate, exhaust, extenuate, faze, finger cymbals,
   firecracker, flap, flummox, flurry, fluster, flutter, fog, force,
   fracas, free-for-all, fuddle, fuss, gab, gabber, gabble, gabbler,
   gamelan, gas, gasbag, gibber, gibble-gabble, gibble-gabbler,
   glockenspiel, go on, goad, gong, gossip, great talker, gruel, gush,
   handbells, haver, hell broke loose, horn, hot-air artist, howl,
   hubbub, hue and cry, hullabaloo, hurtle, hustle, idiophone,
   idle chatterer, jab, jabber, jabberer, jam, jangle, jar, jaw, jay,
   jiggle, jog, joggle, jolt, jostle, jounce, lay low, list,
   loud noise, lyra, magpie, maraca, marimba, maze, metallophone,
   mist, mitigate, mix up, moider, moulin a paroles, muddle, natter,
   noise, noise and shouting, noisemaker, nudge, orchestral bells,
   outcry, palaver, pandemonium, patter, patterer, percussion,
   percussion instrument, percussions, percussive, perplex, perturb,
   piffle, pile drive, poke, pother, pour forth, prate, prater,
   prattle, prattler, press, prod, punch, push, put off, put out,
   racket, raise hell, ram, ram down, ramble, ramble on,
   rattle around, rattle on, rattlebones, rattlebox, rattletybang,
   rattling, recite, reduce, reel off, rhubarb, roar, rock, row,
   ruckle, ruckus, ruction, ruffle, rumble, rumpus, run, run against,
   run on, run through, sap, shake, shake up, shatter, shindy,
   shivaree, shock, shoulder, shove, siren, sizzler, snapper,
   snappers, soften up, speed, spout, spout off, stagger,
   steam whistle, stir, stress, talk away, talk nonsense, talk on,
   tam-tam, tamp, throw into confusion, thrust, thunder, thunderclap,
   ticktack, tintamarre, tintinnabula, tittle-tattle, tonitruone,
   triangle, trouble, tubular bells, tumult, twaddle, twattle,
   unbrace, undermine, unman, unnerve, unsettle, unstrengthen,
   unstring, uproar, upset, utter, vapor, vibes, vibraphone, vibrate,
   waffle, weaken, whistle, whizgig, whizzer, windbag, windjammer,
   word-slinger, xylophone, yak, yakkety-yak