The Collaborative International Dictionary of English v.0.48:

Fade \Fade\, v. i. [imp. & p. p. Faded; p. pr. & vb. n.
   Fading.] [OE. faden, vaden, prob. fr. fade, a.; cf. Prov.
   D. vadden to fade, wither, vaddigh languid, torpid. Cf.
   Fade, a., Vade.]
   1. To become fade; to grow weak; to lose strength; to decay;
      to perish gradually; to wither, as a plant.
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            The earth mourneth and fadeth away.   --Is. xxiv. 4.
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   2. To lose freshness, color, or brightness; to become faint
      in hue or tint; hence, to be wanting in color. "Flowers
      that never fade." --Milton.
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   3. To sink away; to disappear gradually; to grow dim; to
      vanish.
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            The stars shall fade away.            --Addison
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            He makes a swanlike end,
            Fading in music.                      --Shak.
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The Collaborative International Dictionary of English v.0.48:

Fading \Fad"ing\, a.
   Losing freshness, color, brightness, or vigor. -- n. Loss of
   color, freshness, or vigor. -- Fad"ing*ly, adv. --
   Fad"ing*ness, n.
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The Collaborative International Dictionary of English v.0.48:

Fading \Fad"ing\, n.
   An Irish dance; also, the burden of a song. "Fading is a fine
   jig." [Obs.] --Beau. & Fl.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fading
    n 1: weakening in force or intensity; "attenuation in the volume
         of the sound" [syn: attenuation, fading]

Moby Thesaurus II by Grady Ward, 1.0:

177 Moby Thesaurus words for "fading":
   achromatization, aging, atmospherics, blackout, blanching, blaring,
   blasting, bleach, bleaching, blind spot, blocking, brittle,
   capricious, changeable, comedown, coming apart, corruptible,
   cracking, crawling, creeping, crumbling, debasement, decadence,
   decadency, decadent, deciduous, declension, declination, decline,
   declining, decoloration, decolorization, decolorizing, deformation,
   degeneracy, degenerate, degenerateness, degeneration, degradation,
   dematerialization, demotion, departure, depravation, depravedness,
   depreciation, derogation, descent, deteriorating, deterioration,
   devolution, diminishing, disappearance, disappearing,
   discoloration, disintegrating, dispersion, dissipation,
   dissolution, dissolving, doting, downtrend, downturn,
   downward mobility, downward trend, draining, drift, drooping, drop,
   dwindling, dying, ebb, ebbing, eclipse, effete, effeteness,
   elimination, ephemeral, erasure, etiolation, evanescence,
   evanescent, evaporating, evaporation, extinction, fade-out,
   fadeaway, fadeout, failing, failure, failure of nerve, fall,
   falling, falling-off, fickle, flagging, fleeting, flitting,
   fly-by-night, flying, fragile, fragmenting, frail, fugacious,
   fugitive, getting on, going, going to pieces, growing old,
   impermanent, impetuous, impulsive, inconstant, insubstantial,
   interference, involution, languishing, lapse, lightening,
   loss of tone, madder bleach, marcescent, market bleach, melting,
   momentary, mortal, mutable, noise, nondurable, nonpermanent,
   occultation, paling, passing, perishable, pining, receding,
   reception, regression, regressive, retiring, retreating,
   retrocession, retrogradation, retrograde, retrogression,
   retrogressive, senescent, short-lived, shrinking, shriveling,
   sinking, sliding, slippage, slipping, slump, slumping, static,
   subsiding, tabetic, temporal, temporary, transient, transitive,
   transitory, undurable, unenduring, unstable, vanishing,
   vanishing point, volatile, wane, waning, wasting, whitening,
   wilting, wipe, withering, worsening