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

These are rooms that encourage guests to slow down, disconnect from digital intrusions, and recenter themselves. — Robb Report Studio, Robb Report, 3 Oct. 2026

Veterans, retirees and lawmakers spoke out — against its scale, its cost, its lack of Congressional approval, its gaudiness, its intrusion on nearby Arlington National Cemetery and more — next to a mockup made of tarp. — Rachel Treisman, NPR, 2 Oct. 2026

In July, an orchestrated multi-agent framework ran a four-day intrusion against Taiwan’s justice ministry, cracking employee accounts, extracting personnel records, SSO client secrets and database credentials. — Taylor Morgan, Forbes.com, 2 Oct. 2026

By then, the decision has already been made for them, and made expensively, because water intrusion means the project now includes decking, insulation and drywall, not just shingles. — Hanna Wickes, Miami Herald, 1 Oct. 2026

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)