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

Water that gets behind the finished siding can then get behind the all-important flashing meant to prevent this water intrusion. —Tim Carter, Hartford Courant, 9 Aug. 2025

The Duke and Duchess cited the unbearable intrusions of the U.K. press and a lack of support from their palace as their reasons for their exit. —Stephanie Nolasco , Ashley Papa, FOXNews.com, 6 Aug. 2025

Please be aware that this is a potential privacy intrusion nightmare. —Lance Eliot, Forbes.com, 5 Aug. 2025

Don’t be fooled by his cutting of the federal workforce; Trump has taken big government to a new level of intrusion. —Tom Zirpoli, Baltimore Sun, 29 July 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)