The Collaborative International Dictionary of English v.0.48:

Interruption \In`ter*rup"tion\, n. [L. interruptio: cf. F.
   interruption.]
   [1913 Webster]
   1. The act of interrupting, or breaking in upon.
      [1913 Webster]

   2. The state of being interrupted; a breach or break, caused
      by the abrupt intervention of something foreign;
      intervention; interposition. --Sir M. Hale.
      [1913 Webster]

            Lest the interruption of time cause you to lose the
            idea of one part.                     --Dryden.
      [1913 Webster]

   3. Obstruction caused by breaking in upon course, current,
      progress, or motion; stop; hindrance; as, the author has
      met with many interruptions in the execution of his work;
      the speaker or the argument proceeds without interruption.
      [1913 Webster]

   4. Temporary cessation; intermission; suspension.
      [1913 Webster]

WordNet (r) 3.0 (2006):

interruption
    n 1: an act of delaying or interrupting the continuity; "it was
         presented without commercial breaks"; "there was a gap in
         his account" [syn: break, interruption, disruption,
         gap]
    2: some abrupt occurrence that interrupts an ongoing activity;
       "the telephone is an annoying interruption"; "there was a
       break in the action when a player was hurt" [syn:
       interruption, break]
    3: a time interval during which there is a temporary cessation
       of something [syn: pause, intermission, break,
       interruption, suspension]

Moby Thesaurus II by Grady Ward, 1.0:

173 Moby Thesaurus words for "interruption":
   abeyance, arrest, arrestation, arrestment, blockage, blocking,
   breach, break, caesura, cease, cease-fire, ceasing, cessation,
   check, clearance, clogging, closing up, closure, coffee break,
   cold storage, constriction, cramp, day off, delay, detainment,
   detention, discontinuity, disruption, distance between,
   disturbance, doldrums, dormancy, double space, downtime, drop,
   em space, en space, encroachment, entrance, entrenchment, fissure,
   fixation, foot-dragging, freeboard, gap, hair space, half space,
   half time, half-time intermission, hampering, hesitation, hiatus,
   hindering, hindrance, holdback, holdup, holiday, impediment,
   impingement, imposition, impropriety, inappropriateness,
   inauspiciousness, inconvenience, incursion, inexpedience,
   infelicity, infiltration, influx, infringement, inhibition,
   injection, inopportuneness, inopportunity, inroad, insinuation,
   intempestivity, interference, interim, interjection, interloping,
   interlude, intermediate space, intermezzo, intermission,
   intermittence, interposition, interposure, interregnum, interspace,
   interstice, interval, intervention, intrusion, invasion,
   irrelevance, irruption, jump, lacuna, lapse, latency, lateness,
   layoff, leap, leeway, let, letup, lull, margin, negativism,
   nuisance value, obstruction, obstructionism, obtrusion, occlusion,
   off-time, opposition, pause, plateau, point of repose, prematurity,
   quiescence, quiescency, quiet spell, recess, relief, remission,
   rent, repression, resistance, respite, rest, resting point,
   restraint, restriction, retardation, retardment, rift, room,
   rupture, setback, single space, space, space between, split,
   squeeze, stand-down, stay, stop, stopping, stranglehold, stricture,
   suppression, surcease, suspension, time interval, time off,
   time out, trespass, trespassing, truce, unfavorableness, unfitness,
   unfittingness, unfortunateness, unlawful entry, unpropitiousness,
   unripeness, unseasonableness, unsuitability, untimeliness,
   vacation, wrongness