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

Creating a physical barrier to prevent any intrusion is a challenge, Laird said. Kelly Yamanouchi, ajc, "Fence jumpers highlight security vulnerability at Hartsfield-Jackson," 12 July 2018 If these processes aren’t complex enough already, Rignot noted that the factors affecting warm water intrusion in Greenland are completely different from those in Antarctica. Chelsea Harvey, Scientific American, "Why Are Glaciers Melting from the Bottom? It’s Complicated," 12 Apr. 2018 Uber failed to disclose the hack when it was being investigated for a similar intrusion that happened in 2014. David Rovella,, "Your Evening Briefing," 12 Apr. 2018 Such extreme warm intrusions in the Arctic, once rare, are becoming more routine, research has shown. Mark Schleifstein,, "Our Drowning Coast: A conversation with Mark Schleifstein," 28 Feb. 2018 Riley turns the dull art of cold-calling into a literal intrusion, visualizing Cash’s desk smashing through the ceilings of his customers, and turning his phone conversations into face-to-face confrontations. David Sims, The Atlantic, "Sorry to Bother You Is Fizzy, Flawed, and Fascinating," 6 July 2018 The department said the sanctions were a response to a number of cyberattacks, including last year’s NotPetya attack, as well as intrusions into the U.S. energy grid and global network infrastructure. Time, "U.S. Hits Russian Firms With Sanctions, Citing Cyberattacks," 11 June 2018 Many journalists consider reviews of their records by law enforcement to identify sources as an intrusion on their First Amendment protections. Steven T. Dennis,, "Ex-Senate Intelligence Security Chief Charged in FBI Leak Probe," 8 June 2018 Since seizing a journalist’s records is so delicate – and potentially an intrusion on their First Amendment rights – there are special regulations the Justice Department must follow. Margaret Hartmann, Daily Intelligencer, "Justice Department Seizes New York Times Reporter’s Records in Leak Probe," 8 June 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

16 Sep 2018

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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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