The Collaborative International Dictionary of English v.0.48:

Discontinuity \Dis*con`ti*nu"i*ty\, n.
   Want of continuity or cohesion; disunion of parts.
   "Discontinuity of surface." --Boyle.
   [1913 Webster]

WordNet (r) 3.0 (2006):

discontinuity
    n 1: lack of connection or continuity [ant: continuity]

Moby Thesaurus II by Grady Ward, 1.0:

176 Moby Thesaurus words for "discontinuity":
   Doppler effect, about-face, abstraction, accommodation, adaptation,
   adjustment, alienation, alteration, amelioration, apostasy,
   arrearage, arrhythmia, betterment, breach, break, brokenness,
   caesura, capriciousness, change, change of heart, changeableness,
   choppiness, clearance, constructive change, continuity, conversion,
   defalcation, defect, defection, deficiency, deficit, degeneration,
   degenerative change, deracination, desultoriness, detachment,
   deterioration, deviation, difference, disarrangement,
   disarticulation, disassociation, disconnectedness, disconnection,
   disengagement, disjointing, disjunction, dislocation, displacement,
   distance between, disunion, divergence, diversification, diversion,
   diversity, division, divorce, divorcement, double space,
   eccentricity, em space, en space, erraticness, fibrillation,
   fitfulness, fits and starts, fitting, flip-flop, fluctuation,
   forcible shift, freeboard, gap, gradual change, hair space,
   half space, heterotopia, hiatus, hole, improvement, incoherence,
   inconstancy, interim, intermediate space, intermittence,
   interruption, interspace, interstice, interval, irregularity,
   isolation, jerkiness, jump, lack, lacuna, leap, leeway, luxation,
   margin, melioration, missing link, mitigation, modification,
   modulation, need, nonuniformity, omission, opening, outage,
   overthrow, parting, partition, patchiness, qualification,
   radical change, re-creation, realignment, red shift, redesign,
   reform, reformation, remaking, removal, renewal, reshaping,
   restructuring, reversal, revival, revivification, revolution,
   ripping out, room, roughness, segmentation, separation, separatism,
   shift, shortage, single space, space, space between, spasticity,
   sporadicity, sporadicness, spottiness, stagger, subdivision,
   subtraction, sudden change, switch, time interval, total change,
   transition, turn, turnabout, ullage, uncertainty, unevenness,
   unhinging, unjointing, unmethodicalness, unpredictability,
   unsteadiness, unsystematicness, upheaval, uprooting, variability,
   variation, variety, violent change, want, wantage, whimsicality,
   withdrawal, wobble, worsening, zoning