noun
ir·rup·tion i-ˈrəp-shən
plural irruptions
: an act or instance of irrupting: such as
a: a sudden, violent, or forcible entry : a rushing or bursting in
… the assassination still feels like a primal catastrophe—an irruption of inexplicable evil as horrifying as any supernatural bogeyman.
—Ross Douthat
b: a sudden and violent invasion
… begins not with Hitler's attack on Poland, but with the Japanese irruption into Outer Mongolia in July 1939…
—John Gooch
c ecology : a sudden sharp increase in the relative numbers of a natural population usually associated with favorable alteration of the environment
The owl's appearance came during an irruption, a huge southward migration of snowy owls from their arctic territories that, this year, followed a successful breeding period.
—Scott Carroll
Mr. Trump’s critics, and his fans too, preferred to think of him as a unique irruption into American history. But Mr. Bannon was right in thinking that most of his instincts and his policies have roots going way back. Before the aviator Charles Lindbergh helped lead the America First Committee to keep the United States out of World War II, Woodrow Wilson had used the slogan “America First” in his doomed 1916 pledge to keep America out of World War I. The press baron William Randolph Hearst used it in his campaigns almost as often as he played up the threat of Chinese immigration. (Orson Welles’s “Citizen Kane,” based on Mr. Hearst, is Mr. Trump’s favorite film.) In the 1920s, the Ku Klux Klan took up the slogan, and as recently as 2016, David Duke, a former leader of the Klan, ran for a Louisiana Senate seat as an “America First” candidate.
| Ferdinand Mount, Conservatives Used to Rule the World. What Happened?