irruption

irruption
    n 1: a sudden violent entrance; a bursting in; "the recent
         irruption of bad manners"
    2: a sudden sharp increase in the relative numbers of a
       population
    3: a sudden violent spontaneous occurrence (usually of some
       undesirable condition); "the outbreak of hostilities" [syn:
       {outbreak}, {eruption}, {irruption}]
    

Irruption \Ir*rup"tion\, n. [L. irruptio: cf. F. irruption. See
   {Irrupted}.]
   [1913 Webster]
   1. A bursting in; a sudden, violent rushing into a place; as,
      irruptions of the sea.
      [1913 Webster]

            Lest evil tidings, with too rude irruption
            Hitting thy aged ear, should pierce too deep.
                                                  --Milton.
      [1913 Webster]

   2. A sudden and violent inroad, or entrance of invaders; as,
      the irruptions of the Goths into Italy. --Addison.

   Syn: Invasion; incursion; inroad. See {Invasion}.
        [1913 Webster]
    

58 Moby Thesaurus words for "irruption":
      air attack, air raid, air strike, blaze, boarding, burst,
      convulsion, cyclone, encroachment, entrance, entrenchment,
      eruption, escalade, explosion, fire raid, fit, flare-up, foray,
      gale, gust, hurricane, impingement, imposition, incursion,
      infiltration, influx, infringement, injection, inroad, insinuation,
      interference, interjection, interloping, interposition,
      interposure, interruption, intervention, intrusion, invasion,
      obtrusion, outbreak, outburst, paroxysm, raid, razzia,
      saturation raid, scaling, seizure, shuttle raid, spasm, storm,
      tempest, tornado, trespass, trespassing, unlawful entry, upheaval,
      whirlwind