Definition of irrupt
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 irrupted in a fervor of patriotism — Time>
Did You Know?
Irrupt and "erupt" have existed as discrete words since the 1800s. Both are descendants of the Latin verb rumpere, which means "to break," but "irrupt" has affixed to it the prefix ir- (in the sense "into") while "erupt" begins with the prefix e- (meaning "out"). So "to irrupt" was originally to rush in, and "to erupt" was to burst out. But it's sometimes hard to distinguish the precise direction of a violent rush, and "irrupt" came to be used as a synonym of "erupt" in the senses "to become active or violent especially suddenly" and "to break forth," as in our example sentence.
Origin of irrupt
Latin irruptus, past participle of irrumpere, from in- + rumpere to break — more at reave
First Known Use: 1886
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