ə̇ˈrəpshən noun
( -s )
Etymology: Latin irruption-, irruptio, from irruptus + -ion-, -io -ion
: an act or instance of irrupting: as
a. : a sudden violent or forceable entry : a rushing or bursting in
the current irruption of bad manners into everyday life
an irruption of water through a break in the dike
b. : a sudden and violent invasion
the irruptions of the Goths into Italy
c. : eruption 1
d. : a sudden sharp increase in the relative numbers of a natural population usually associated with favorable alteration of the environment