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):

wavering
    adj 1: uncertain in purpose or action [syn: vacillant,
           vacillating, wavering]
    n 1: indecision in speech or action [syn: hesitation,
         vacillation, wavering]
    2: the quality of being unsteady and subject to changes; "he
       kept a record of price fluctuations" [syn: fluctuation,
       wavering]

Moby Thesaurus II by Grady Ward, 1.0:

258 Moby Thesaurus words for "wavering":
   adrift, aflicker, afloat, agnostic, alternating, alternation,
   ambiguous, amorphous, bickering, blinking, broken, capricious,
   capriciousness, careening, catchy, chancy, changeability,
   changeable, changeableness, changeful, changing, choppiness,
   choppy, dancing, dappleness, desultory, deviable, deviating,
   deviation, deviative, deviatory, dicey, dickey, difference,
   different, differentiation, disconnected, discontinuous, disorder,
   disorderly, divaricate, divarication, divergence, divergent,
   diversification, diversified, diversiform, dizzy, doubting,
   eccentric, equivocal, equivocation, erose, erratic, faltering,
   fast and loose, fickle, fitful, flashing, flickering, flickery,
   flicky, flighty, flitting, fluctuant, fluctuating, fluctuation,
   fluctuational, fluttering, fluttery, freakish, frequency,
   frequency band, frequency spectrum, giddy, guttering, halting,
   harmonic, harmonic motion, herky-jerky, hesitancy, hesitant,
   hesitating, heteroclite, immethodical, impetuous, impulsive,
   incalculable, inconsistency, inconsistent, inconstancy, inconstant,
   indecision, indecisive, indemonstrable, inequality, infirm,
   insecure, instability, intermittent, intermitting, irregular,
   irregularity, irresolute, irresolution, irresponsible, jagged,
   jerkiness, jerky, lambent, libration, libratory, lurching, mazy,
   mercurial, mercuriality, moody, motley, motleyness, mutability,
   mutable, nonconformism, nonconformist, nonconformity, nonstandard,
   nonstandardization, nonuniform, nonuniformity, nutation,
   nutational, oscillating, oscillation, oscillatory, patchy,
   pendular, pendulating, pendulation, pendulous, periodic,
   periodicity, playing, pluralism, pluralistic, polysemous,
   quivering, quivery, ragged, raggedness, rambling, resonance,
   resonance frequency, resonant, restless, rootless, rough, roving,
   scatterbrained, scrappy, seesawing, shaky, shapeless, shifting,
   shifty, shilly-shally, shilly-shallying, shuffling, skeptical,
   snatchy, spasmatic, spasmic, spasmodic, spastic, spineless,
   spluttering, sporadic, spotty, sputtering, sputtery, staggering,
   stroboscopic, teeter-tottering, teetering, tottering, touch-and-go,
   unaccountable, uncertain, unconfirmable, unconformism,
   unconformity, uncontrolled, unconvinced, undependable,
   undisciplined, undivinable, unequable, unequal, uneven, unevenness,
   unfixed, unforeseeable, unmethodical, unmetrical, unorthodox,
   unorthodoxy, unpersuaded, unpredictable, unprovable, unregular,
   unreliable, unrestrained, unrhythmical, unsettled, unstable,
   unstable as water, unstaid, unsteadfast, unsteadiness, unsteady,
   unsure, unsystematic, ununiform, unverifiable, vacillating,
   vacillation, vacillatory, vagrant, variability, variable,
   variation, variegated, variegation, variety, variform, various,
   variousness, varying, veering, versatility, vibrancy, vibratile,
   vibratility, vibrating, vibration, vibratory, vicissitude,
   vicissitudinary, vicissitudinous, volatile, wandering, wanton,
   wavery, wavy, wayward, weak, whimsical, wishy-washy, wobbling,
   wobbly