irruption Meaning, Definition & Usage

  1. noun a sudden violent entrance; a bursting in
    • the recent irruption of bad manners
  2. noun a sudden sharp increase in the relative numbers of a population
  3. noun a sudden violent spontaneous occurrence (usually of some undesirable condition)
    outbreak; eruption.
    • the outbreak of hostilities

WordNet

Ir*rup"tion noun
Etymology
L. irruptio: cf. F. irruption. See Irrupted.
Definitions
  1. A bursting in; a sudden, violent rushing into a place; as, irruptions of the sea.
    Lest evil tidings, with too rude irruption Hitting thy aged ear, should pierce too deep. Milton.
  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.

Webster 1913