The Collaborative International Dictionary of English v.0.48:

Shift \Shift\ (sh[i^]ft), v. t. [imp. & p. p. Shifted; p. pr.
   & vb. n. Shifting.] [OE. shiften, schiften, to divide,
   change, remove. AS. sciftan to divide; akin to LG. & D.
   schiften to divide, distinguish, part Icel. skipta to divide,
   to part, to shift, to change, Dan skifte, Sw. skifta, and
   probably to Icel. sk[imac]fa to cut into slices, as n., a
   slice, and to E. shive, sheave, n., shiver, n.]
   1. To divide; to distribute; to apportion. [Obs.]
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            To which God of his bounty would shift
            Crowns two of flowers well smelling.  --Chaucer.
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   2. To change the place of; to move or remove from one place
      to another; as, to shift a burden from one shoulder to
      another; to shift the blame.
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            Hastily he schifte him[self].         --Piers
                                                  Plowman.
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            Pare saffron between the two St. Mary's days,
            Or set or go shift it that knowest the ways.
                                                  --Tusser.
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   3. To change the position of; to alter the bearings of; to
      turn; as, to shift the helm or sails.
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            Carrying the oar loose, [they] shift it hither and
            thither at pleasure.                  --Sir W.
                                                  Raleigh.
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   4. To exchange for another of the same class; to remove and
      to put some similar thing in its place; to change; as, to
      shift the clothes; to shift the scenes.
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            I would advise you to shift a shirt.  --Shak.
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   5. To change the clothing of; -- used reflexively. [Obs.]
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            As it were to ride day and night; and . . . not to
            have patience to shift me.            --Shak.
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   6. To put off or out of the way by some expedient. "I shifted
      him away." --Shak.
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   To shift off, to delay; to defer; to put off; to lay aside.


   To shift the scene, to change the locality or the
      surroundings, as in a play or a story.
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            Shift the scene for half an hour;
            Time and place are in thy power.      --Swift.
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The Collaborative International Dictionary of English v.0.48:

Shifting \Shift"ing\, a.
   1. Changing in place, position, or direction; varying;
      variable; fickle; as, shifting winds; shifting opinions or
      principles.
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   2. Adapted or used for shifting anything.
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   Shifting backstays (Naut.), temporary stays that have to be
      let go whenever the vessel tacks or jibes.

   Shifting ballast, ballast which may be moved from one side
      of a vessel to another as safety requires.

   Shifting center. See Metacenter.

   Shifting locomotive. See Switching engine, under
      Switch.
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WordNet (r) 3.0 (2006):

shifting
    adj 1: continuously varying; "taffeta with shifting colors"
    2: changing position or direction; "he drifted into the shifting
       crowd"; "their nervous shifting glances"; "shifty winds"
       [syn: shifting, shifty]
    3: (of soil) unstable; "shifting sands"; "unfirm earth" [syn:
       shifting, unfirm]
    n 1: the act of moving from one place to another; "his constant
         shifting disrupted the class" [syn: shift, shifting]

Moby Thesaurus II by Grady Ward, 1.0:

227 Moby Thesaurus words for "shifting":
   aberrancy, aberrant, aberration, aberrative, adrift, afloat,
   alternating, alternation, amorphous, bend, bias, bickering,
   boggling, branching off, capricious, captiousness, caviling,
   changeable, changeful, chicane, chicanery, circuitous,
   circuitousness, circumforaneous, corner, crook, curve, dangerous,
   declination, departing, departure, desultory, detour, deviable,
   deviance, deviancy, deviant, deviating, deviation, deviative,
   deviatory, devious, deviousness, digression, digressive,
   discursion, discursive, divagation, divagatory, divarication,
   divergence, diversion, dizzy, dodging, dogleg, double, drift,
   drifting, eccentric, equivocation, errant, errantry, erratic,
   evasion, excursion, excursive, excursus, exorbitation,
   fast and loose, fencing, fickle, fitful, flickering, flighty,
   flitting, floating, fluctuating, fluctuation, footloose,
   footloose and fancy-free, freakish, fugitive, gadding, giddy,
   gypsy-like, gypsyish, hairpin, hairsplitting, hazardous, hedging,
   impetuous, impulsive, inconsistent, inconstant, indecisive,
   indirect, indirection, infirm, insecure, insubstantial, irregular,
   irresolute, irresponsible, labyrinthine, landloping,
   logic-chopping, mazy, meandering, mercurial, migrational,
   migratory, moody, nit-picking, nomad, nomadic, obliquity,
   oscillation, out-of-the-way, paltering, parrying, pendulation,
   pererration, perilous, pettifoggery, planetary, precarious,
   prevarication, provisional, pussyfooting, quibbling, rambling,
   ranging, restless, risky, roaming, roving, scatterbrained,
   seesawing, serpentine, shaky, shapeless, sheer, shift,
   shifting course, shifting path, shifty, shuffling, sidestepping,
   skew, slant, slippery, snaky, spasmodic, spineless, straggling,
   stray, straying, strolling, subterfuge, sweep, swerve, swerving,
   swinging, tack, teeter-tottering, teetering, temporary, tentative,
   tergiversation, ticklish, tottering, traipsing, transient,
   transitory, transmigratory, treacherous, trichoschistism, turn,
   turning, twist, twisting, unaccountable, uncertain, uncontrolled,
   undependable, undirected, undisciplined, unfaithworthy, unfixed,
   unpredictable, unreliable, unrestrained, unsettled, unsolid,
   unsound, unstable, unstable as water, unstaid, unsteadfast,
   unsteady, unsubstantial, unsure, untrustworthy, vacillating,
   vacillation, vagabond, vagrant, variable, variation, veer, veering,
   vicissitude, vicissitudinary, vicissitudinous, volatile, wandering,
   wanton, warp, wavering, wavery, wavy, wayward, whimsical, winding,
   wishy-washy, yaw, zigzag