v.
Pronunciation: i- ' r ə pt
Function: intransitive verb
Etymology: Latin irruptus, past participle of irrumpere, from in- + rumpere to break ― more at REAVE
Date: 1886
1 : to rush in forcibly or violently
2 of a natural population : to undergo a sudden upsurge in numbers especially when natural ecological balances and checks are disturbed
3 : ERUPT 1C <the crowd irrupt ed in a fervor of patriotism ― Time >
– ir · rup · tion \ - ' r ə p-sh ə n \ noun