in·​tru·​sion | \ in-ˈtrü-zhən How to pronounce intrusion (audio) \

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 The intrusion of summer warmth into our colder seasons is presenting a challenge for native plant and animal species whose life cycles are scheduled around the once-reliable seasonal changes of the temperate North American climate. Paul Douglas, Star Tribune, "Shorts-Worthy Friday and a Fine Weekend as "Delta" Approaches Louisiana," 7 Oct. 2020 In this era of the ubiquitous smartphone, even an unscheduled call can feel like an intrusion; showing up unannounced at someone’s house can seem outright belligerent, and a bit antique. Patrick Radden Keefe, The New Yorker, "Why Private Eyes Are Everywhere Now," 28 Sep. 2020 Shielded cabling protects from interference, and in the case of undersea telecommunications and some overland applications, physical intrusion into the cabling itself. Caroline Delbert, Popular Mechanics, "How an Older TV Screwed Up an Entire Village’s Internet," 2 Oct. 2020 New clues indicate that APT28 may be behind a mysterious intrusion that US officials disclosed last week. Andy Greenberg, Wired, "Russia’s Fancy Bear Hackers Likely Penetrated a US Federal Agency," 1 Oct. 2020 One of the people familiar with the investigation said early analysis of the intrusion indicated that the hackers may not have been targeting Washington but rather happened upon -- and took advantage of -- flaws in the state’s cybersecurity system. Kartikay Mehrotra,, "Hackers Have Infiltrated Many of Washington State’s Agencies," 27 Sep. 2020 Those rulings found that the warrants violated a federal law that requires police to minimize the intrusion of the cameras and focus only on crimes. Marc Freeman,, "Prosecutors drop charges against Patriots owner Robert Kraft after cops bungled sex sting," 24 Sep. 2020 As the ducks recover, they are moved to a large, plastic swimming tubs, often with floating mats, with a tent-like canopy enclosure to keep them calm and safe from intrusion. Tom Stienstra,, "Inside Klamath Refuge’s ‘Duck Hospital’: Crews save 2,000 birds infected with avian botulism," 1 Sep. 2020 Environmental intrusion, decades of government inaction, and high winds have forced the situation out of control. Noah Robertson, The Christian Science Monitor, "California wildfires: Why this year is so intense," 26 Aug. 2020

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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Time Traveler for intrusion

Time Traveler

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

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Statistics for intrusion

Last Updated

25 Oct 2020

Cite this Entry

“Intrusion.” Dictionary, Merriam-Webster, Accessed 29 Oct. 2020.

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More Definitions for intrusion


in·​tru·​sion | \ in-ˈtrü-zhən How to pronounce intrusion (audio) \

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 How to pronounce intrusion (audio) \

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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