The Collaborative International Dictionary of English v.0.48:

Waver \Wa"ver\, n. [From Wave, or Waver, v.]
   A sapling left standing in a fallen wood. [Prov. Eng.]
   --Halliwell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Waver \Wa"ver\, v. i. [imp. & p. p. Wavered; p. pr. & vb. n.
   Wavering.] [OE. waveren, from AS. w[ae]fre wavering,
   restless. See Wave, v. i.]
   [1913 Webster]
   1. To play or move to and fro; to move one way and the other;
      hence, to totter; to reel; to swing; to flutter.
      [1913 Webster]

            With banners and pennons wavering with the wind.
                                                  --Ld. Berners.
      [1913 Webster]

            Thou wouldst waver on one of these trees as a terror
            to all evil speakers against dignities. --Sir W.
                                                  Scott.
      [1913 Webster]

   2. To be unsettled in opinion; to vacillate; to be
      undetermined; to fluctuate; as, to water in judgment.
      [1913 Webster]

            Let us hold fast . . . without wavering. --Heb. x.
                                                  23.
      [1913 Webster]

            In feeble hearts, propense enough before
            To waver, or fall off and join with idols. --Milton.
      [1913 Webster]

   Syn: To reel; totter; vacillate. See Fluctuate.
        [1913 Webster]

WordNet (r) 3.0 (2006):

waver
    n 1: someone who communicates by waving
    2: the act of pausing uncertainly; "there was a hesitation in
       his speech" [syn: hesitation, waver, falter,
       faltering]
    3: the act of moving back and forth [syn: waver, flutter,
       flicker]
    v 1: pause or hold back in uncertainty or unwillingness;
         "Authorities hesitate to quote exact figures" [syn:
         hesitate, waver, waffle]
    2: be unsure or weak; "Their enthusiasm is faltering" [syn:
       falter, waver]
    3: move hesitatingly, as if about to give way [syn: falter,
       waver]
    4: move or sway in a rising and falling or wavelike pattern;
       "the line on the monitor vacillated" [syn: fluctuate,
       vacillate, waver]
    5: move back and forth very rapidly; "the candle flickered"
       [syn: flicker, waver, flitter, flutter, quiver]
    6: sway to and fro [syn: waver, weave]
    7: give off unsteady sounds, alternating in amplitude or
       frequency [syn: quaver, waver]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "waver":
   alternate, back and fill, beat, beating, bicker, blench, bob,
   bobble, boggle, careen, change, coggle, dance, dangle, demur,
   dither, ebb and flow, equivocate, falter, fight shy of, flap,
   flick, flicker, flinch, flip, flit, flitter, flop, flounder,
   fluctuate, flutter, go pitapat, go through phases, gutter, halt,
   hang back, hang off, have qualms, hem and haw, hesitate, hold off,
   librate, lurch, make bones about, nutate, oscillate, palpitate,
   palpitation, palter, pause, pendulate, pitapat, pitch,
   pitter-patter, play, pull back, pulse, quail, quiver, recoil, reel,
   resonate, ring the changes, rock, roll, scruple, seesaw, shake,
   shift, shilly-shally, shrink, shuffle, shy, shy at, slat, splutter,
   sputter, stagger, stick at, stickle, strain, swag, sway, swing,
   swinging, teeter, teeter-totter, tergiversate, throb, toss, totter,
   trim, turn, vacillate, vary, vibrate, wag, waggle, wave,
   wax and wane, whiffle, wince, wobble