The Collaborative International Dictionary of English v.0.48:

Divergence \Di*ver"gence\, Divergency \Di*ver"gen*cy\, n. [Cf.
   F. divergence.]
   1. A receding from each other in moving from a common center;
      the state of being divergent; as, an angle is made by the
      divergence of straight lines.
      [1913 Webster]

            Rays come to the eye in a state of divergency.
                                                  --??????.
      [1913 Webster]

   2. Disagreement; difference.
      [1913 Webster]

            Related with some divergence by other writers. --Sir
                                                  G. C. Lewis.
      [1913 Webster]

WordNet (r) 3.0 (2006):

divergence
    n 1: the act of moving away in different direction from a common
         point; "an angle is formed by the divergence of two
         straight lines" [syn: divergence, divergency]
    2: a variation that deviates from the standard or norm; "the
       deviation from the mean" [syn: deviation, divergence,
       departure, difference]
    3: an infinite series that has no limit [syn: divergence,
       divergency] [ant: convergence, convergency]
    4: a difference between conflicting facts or claims or opinions;
       "a growing divergence of opinion" [syn: discrepancy,
       disagreement, divergence, variance]

Moby Thesaurus II by Grady Ward, 1.0:

347 Moby Thesaurus words for "divergence":
   aberrance, aberrancy, aberration, abnormality, abnormity,
   about-face, accommodation, adaptation, adjustment,
   aesthetic distance, alienation, alteration, amelioration,
   amorphism, anomalism, anomalousness, anomaly, antagonism, apostasy,
   argumentation, attenuation, bad copy, bad likeness, bend,
   betterment, bias, branching off, breach, breach of friendship,
   break, broadcast, broadcasting, camouflage, capriciousness, change,
   change of heart, changeability, changeableness, choppiness,
   circuitousness, circumfusion, clashing, clearance, cleavage, cleft,
   compass, conceit, conflict, constructive change, continuity,
   contradiction, contrariety, contrast, controversy, conversion,
   corner, crackpotism, crank, crankiness, crankism, crook,
   crosswiseness, crotchet, crotchetiness, curve, dappleness,
   declination, deep space, defection, deflection, deflexure,
   degeneration, degenerative change, departure, depths of space,
   derangement, deterioration, detour, deviance, deviancy, deviation,
   deviousness, diagonality, difference, differentiation,
   differentness, differing, diffraction, diffusion, digression,
   dilution, disaccord, disaccordance, disaffection, disagreeing,
   disagreement, disconformity, discongruity, discontinuity, discord,
   discordance, discordancy, discrepancy, discreteness, discursion,
   disfavor, disguise, disharmony, disorder, disparity, dispensation,
   dispersal, dispersion, disruption, dissemblance, dissemination,
   dissension, dissent, dissidence, dissimilarity, dissimilation,
   dissimilitude, dissipation, dissonance, distance, distinction,
   distinctness, distribution, disunion, disunity, divagation,
   divarication, divergency, diversification, diversion, diversity,
   dividedness, division, dogleg, dottiness, double, drift, drifting,
   eccentricity, errantry, erraticism, erraticness, estrangement,
   evaporation, excursion, excursus, exorbitation, expansion, extent,
   faction, falling-out, far cry, farness, fitting, flip-flop,
   fragmentation, freakiness, freakishness, gradual change, hairpin,
   heterogeneity, heteromorphism, idiocrasy, idiosyncrasy,
   improvement, inaccordance, incommensurability, incomparability,
   incompatibility, incongruity, inconsistency, inconsonance,
   inconstancy, indirection, indirectness, inequality, inferiority,
   infinity, inharmoniousness, inharmony, instability,
   irreconcilability, irregularity, jarring, jerkiness, kink, leeway,
   length, light-years, makeup, mannerism, margin, melioration,
   mercuriality, mere caricature, mileage, mitigation, mixture,
   modification, modulation, monstrosity, motleyness, mutability,
   negation, nonconformism, nonconformity, nonstandardization,
   nonuniformity, obliqueness, obliquity, oddity, odds, open rupture,
   opposition, oppugnancy, otherness, overthrow, parsecs, parting,
   peculiarity, peppering, pererration, perspective, piece, pluralism,
   poor imitation, propagation, publication, qualification, queerness,
   quip, quirk, quirkiness, radiation, radical change, raggedness,
   rambling, range, re-creation, reach, realignment,
   recall of ambassadors, redesign, reform, reformation, remaking,
   remoteness, renewal, repugnance, reshaping, restructuring,
   reversal, revival, revivification, revolution, rift, rupture,
   scattering, scatterment, schism, separateness, separation, sheer,
   shift, shifting, shifting course, shifting path, shotgun pattern,
   singularity, skew, skewness, slant, sowing, space, span,
   spattering, splay, split, spread, spreading, sprinkling, squint,
   strangeness, straying, stretch, strewing, stride, subnormality,
   sudden change, superiority, sweep, swerve, swerving, swinging,
   switch, tack, teratism, total change, transition, transverseness,
   trick, turn, turnabout, turning, twist, unconformism, unconformity,
   unconventionality, unevenness, unharmoniousness, unlikeness,
   unnaturalism, unnaturalness, unorthodoxy, unresemblance,
   unsameness, unsimilarity, unsteadiness, upheaval, vagary,
   variability, variance, variation, variegation, variety,
   variousness, varying, veer, versatility, violent change,
   volatilization, wandering, warp, wavering, way, ways, whim,
   whimsicality, whimsy, worsening, yaw, zigzag