intrusion

noun

in·​tru·​sion in-ˈtrü-zhən 

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

Earlier this year, Argentina deployed its naval force to patrol its exclusive economic zone (EEZ) to deter foreign vessel intrusions. —Ryan Chan, MSNBC Newsweek, 13 Oct. 2025

His darkly satiric new movie, aptly titled One Battle After Another, opened September 26 to rapturous, or merely stunned, reviews, only to confront a $34 million box office intrusion from Taylor Swift — one that may ironically enhance Anderson’s future Oscar forays. —Peter Bart, Deadline, 9 Oct. 2025

The announcement comes at a time when large-scale attacks on cloud CRM systems have already shaken tech and retail sectors alike, with Salesforce clients such as Google, Allianz and Dior reporting similar intrusions. —FOXNews.com, 7 Oct. 2025

More advanced intrusions bypass sensors completely and target a drone’s internal systems through malware. —Aamir Khollam, Interesting Engineering, 7 Oct. 2025

Word History

Etymology

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

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing intrusion

• anti-intrusion

Rhymes for intrusion

• allusion
• collusion
• conclusion
• confusion
• contusion
• delusion
• diffusion
• effusion
• exclusion
• extrusion
• illusion
• inclusion

Kids Definition

intrusion

noun

in·​tru·​sion in-ˈtrü-zhən 

1

: the act of intruding : the state of being intruded

2

: the entry by force of melted rock into or between other rock formations

Legal Definition

intrusion

noun

in·​tru·​sion in-ˈtrü-zhən 

1

a

: 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 intrusion

—Berger v. New York, 388 U.S. 41 (1968)