irruption (n.) Look up irruption at Dictionary.com
1570s, from Middle French irruption or directly from Latin irruptionem (nominative irruptio) "a breaking in, bursting in, invasion," noun of action from past participle stem of irrumpere, from assimilated form of in- "into, in, on, upon" (see in- (2)) + rumpere (see rupture (n.)). Frequently confused with eruption.