in·​tru·​sion | \ in-ˈtrü-zhən \

Definition of intrusion

1 : the act of intruding or the state of being intruded especially : the act of wrongfully entering upon, seizing, or taking possession of the property of another
2 : the forcible entry of molten rock or magma into or between other rock formations also : the intruded magma

Examples of intrusion in a Sentence

Recent Examples on the Web

That’s when Politico contacted the NRCC with questions about the intrusions, Tuesday’s report said. Dan Goodin, Ars Technica, "Thousands of sensitive emails stolen in intrusion of Republican campaign arm," 4 Dec. 2018 The agencies will also need to tackle the increasing need to balance the amount of freshwater needed in marshes to fight back saltwater intrusion from sea rise. Jenny Staletovich, miamiherald, "Could raising a 90-year-old road fix South Florida's water problems?," 18 June 2018 But elections officials never not disclosed an apparently unrelated, successful intrusion into the website-hosting server on Election Day. Nathaniel Herz, Anchorage Daily News, "Hackers broke partway into Alaska’s election system in 2016. Officials say no damage was done.," 8 May 2018 Brown and water officials throughout the state have said the 1,100 miles of levees in the delta are increasingly vulnerable to earthquakes, flooding and saltwater intrusion from downstream. Peter Fimrite, San Francisco Chronicle, "California’s two-tunnel Delta project is back on track with SoCal water district’s vote," 10 Apr. 2018 For windows or doors that are vulnerable to intrusion from water running downhill or collecting on the ground, get ready to stake some lumber in place. Roy Berendsohn, Popular Mechanics, "The Homeowner's Last-Minute Hurricane Prep Checklist," 25 Aug. 2017 In some unfortunate circumstances, your skin can react badly to the intrusion. Jessica Toscano, SELF, "9 Smart Questions to Ask Before Getting a Tattoo," 9 Nov. 2018 Chinese hacking groups aren't the only ones to have improved their game against intrusion detection and response. Sean Gallagher, Ars Technica, "New data shows China has “taken the gloves off” in hacking attacks on US," 1 Nov. 2018 The Department of Homeland Security is gathering further information about the potential cyber intrusion, a spokesman said by email. Houston Chronicle, "Cyberattack on Energy Transfer Partners' data system overcome," 3 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'intrusion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of intrusion

15th century, in the meaning defined at sense 1

History and Etymology for intrusion

Middle English, from Anglo-French, from Medieval Latin intrusion-, intrusio, from Latin intrudere

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Statistics for intrusion

Last Updated

4 Feb 2019

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Time Traveler for intrusion

The first known use of intrusion was in the 15th century

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More Definitions for intrusion


in·​tru·​sion | \ in-ˈtrü-zhən \

Kids Definition of intrusion

1 : the act of going or forcing in without being wanted
2 : something that goes in or interferes without being wanted The phone call was an unwelcome intrusion.


in·​tru·​sion | \ in-ˈtrü-zhən \

Legal Definition of intrusion

1a : the entry at common law of a stranger after a particular estate of freehold is determined before the person who holds it in remainder or reversion has taken possession
b : the act of wrongfully entering upon, seizing, or taking possession of the property of another
2 : a trespassing on or encroachment upon something (as a right) the Fourth Amendment demands that the showing of justification match the degree of intrusionBerger v. New York, 388 U.S. 41 (1968)

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More from Merriam-Webster on intrusion

Rhyming Dictionary: Words that rhyme with intrusion

Spanish Central: Translation of intrusion

Nglish: Translation of intrusion for Spanish Speakers

Britannica English: Translation of intrusion for Arabic Speakers

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