The Collaborative International Dictionary of English v.0.48:

Upheaval \Up*heav"al\, n.
   The act of upheaving, or the state of being upheaved; esp.,
   an elevation of a portion of the earth's crust. --Lubbock.
   [1913 Webster]

WordNet (r) 3.0 (2006):

upheaval
    n 1: a state of violent disturbance and disorder (as in politics
         or social conditions generally); "the industrial revolution
         was a period of great turbulence" [syn: turbulence,
         upheaval, Sturm und Drang]
    2: a violent disturbance; "the convulsions of the stock market"
       [syn: convulsion, turmoil, upheaval]
    3: (geology) a rise of land to a higher elevation (as in the
       process of mountain building) [syn: upheaval, uplift,
       upthrow, upthrust]
    4: disturbance usually in protest [syn: agitation,
       excitement, turmoil, upheaval, hullabaloo]

Moby Thesaurus II by Grady Ward, 1.0:

142 Moby Thesaurus words for "upheaval":
   about-face, accommodation, adaptation, adjustment, alteration,
   amelioration, apoplexy, apostasy, apotheosis, ascent, assumption,
   beatification, betterment, blaze, bouleversement, break, breakup,
   burst, canonization, cataclysm, catastrophe, change,
   change of heart, changeableness, chaos, clamor, climax, commotion,
   confusion, constructive change, continuity, conversion, convulsion,
   cyclone, defection, degeneration, degenerative change, deification,
   deterioration, deviation, diastrophism, difference, disaster,
   discontinuity, disorder, disruption, disturbance, divergence,
   diversification, diversion, diversity, downfall, elevation,
   enshrinement, erection, eruption, escalation, exaltation,
   explosion, fall, ferment, fit, fitting, flare-up, flip-flop, furor,
   furore, gale, gradual change, gust, heaving, height, hurricane,
   improvement, irruption, lifting, melioration, mitigation,
   modification, modulation, outbreak, outburst, outcry, overthrow,
   overturn, paroxysm, prostration, quake, qualification,
   radical change, raising, re-creation, realignment, rearing,
   redesign, reform, reformation, remaking, renewal, reshaping,
   restructuring, reversal, revival, revivification, revolution,
   sabotage, seizure, shift, spasm, stirring, storm, stroke,
   subversion, sudden change, sursum corda, switch, temblor, tempest,
   tidal wave, tornado, total change, transition, tsunami, tumult,
   turn, turnabout, unrest, upbuoying, upcast, uplift, uplifting,
   upping, uprearing, upset, upthrow, upthrust, upturn, variation,
   variety, violent change, whirlwind, worsening