The Collaborative International Dictionary of English v.0.48:

Falter \Fal"ter\, v. t.
   To thrash in the chaff; also, to cleanse or sift, as barley.
   [Prov. Eng.] --Halliwell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Falter \Fal"ter\, v. i. [imp. & p. p. Faltered; p. pr. & vb.
   n. Faltering.] [OE. falteren, faltren, prob. from fault.
   See Fault, v. & n.]
   1. To hesitate; to speak brokenly or weakly; to stammer; as,
      his tongue falters.
      [1913 Webster]

            With faltering speech and visage incomposed.
                                                  --Milton.
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   2. To tremble; to totter; to be unsteady. "He found his legs
      falter." --Wiseman.
      [1913 Webster]

   3. To hesitate in purpose or action.
      [1913 Webster]

            Ere her native king
            Shall falter under foul rebellion's arms. --Shak.
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   4. To fail in distinctness or regularity of exercise; -- said
      of the mind or of thought.
      [1913 Webster]

            Here indeed the power of disinct conception of space
            and distance falters.                 --I. Taylor.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Falter \Fal"ter\, v. t.
   To utter with hesitation, or in a broken, trembling, or weak
   manner.
   [1913 Webster]

         And here he faltered forth his last farewell. --Byron.
   [1913 Webster]

         Mde me most happy, faltering "I am thine." --Tennyson.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Falter \Fal"ter\, n. [See Falter, v. i.]
   Hesitation; trembling; feebleness; an uncertain or broken
   sound; as, a slight falter in her voice.
   [1913 Webster]

         The falter of an idle shepherd's pipe.   --Lowell.
   [1913 Webster]

WordNet (r) 3.0 (2006):

falter
    n 1: the act of pausing uncertainly; "there was a hesitation in
         his speech" [syn: hesitation, waver, falter,
         faltering]
    v 1: be unsure or weak; "Their enthusiasm is faltering" [syn:
         falter, waver]
    2: move hesitatingly, as if about to give way [syn: falter,
       waver]
    3: walk unsteadily; "The drunk man stumbled about" [syn:
       stumble, falter, bumble]
    4: speak haltingly; "The speaker faltered when he saw his
       opponent enter the room" [syn: bumble, stutter,
       stammer, falter]

Moby Thesaurus II by Grady Ward, 1.0:

190 Moby Thesaurus words for "falter":
   Bebung, abandon hope, back down, back out, balance, bashfulness,
   blench, blunder, bob, bobble, boggle, boggling, bounce, bump,
   careen, career, caution, cautiousness, chatter, chicken,
   chicken out, compunction, dally, dawdle, debate, delay, deliberate,
   demur, demurral, desert under fire, despair, despair of, despond,
   didder, diffidence, dillydally, dither, drag, faltering, fear,
   fight shy of, flag, flinch, flounce, flounder, flutter, funk,
   funk out, get cold feet, give up, give up hope, give way, goof off,
   grimace, halt, hang back, hang in doubt, hang off, have an ague,
   have qualms, haw, hem, hem and haw, hesitance, hesitancy, hesitate,
   hesitating, hesitation, hold off, hover, hum, hum and haw, hustle,
   jactitate, jar, jerk, jib, jig, jigget, jiggle, jog, joggle, jolt,
   jostle, jounce, jump, labor, lag, linger, loiter, lollygag,
   lose courage, lose heart, lose hope, lurch, make bones about,
   mammer, modesty, objection, pause, pitch, pitch and plunge, plunge,
   ponder, protest, pull back, quail, quake, qualm,
   qualm of conscience, qualmishness, quaver, quiver, recoil, reel,
   retreat, rictus, rock, roll, scruple, scrupulosity, scrupulousness,
   scuttle, seethe, shake, shilly-shally, shilly-shallying, shiver,
   shock, shrink, shrinking, shudder, shy, shy at, shyness,
   sink into despair, skedaddle, stagger, stammer, stick at, stickle,
   stickling, stop to consider, straddle the fence, strain, strain at,
   struggle, stumble, stutter, sway, swing, tarry, tentativeness,
   think twice, think twice about, thrash about, tic, topple, toss,
   toss and tumble, toss and turn, totter, trail, tremble, tremolando,
   tremolant, tremolo, tremor, trill, trillet, trilleto, trillo,
   tumble, twitch, twitter, vacillate, vibrate, vibrato, volutation,
   wallop, wallow, waste time, waver, welter, whine, wince, withdraw,
   wobble, yield, yield to despair