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

That kind of political intrusion does not make families safer or stronger. —Austen Erblat, CBS News, 18 Mar. 2026

That minimum first considers what’s required to keep the Biscayne Aquifer, which is a source of drinking water for 3 to 4 million people in South Florida, from getting too low and risking saltwater intrusion. —Ashley Miznazi, Miami Herald, 16 Mar. 2026

The audience never feels that intrusion. —Murtada Elfadl, Variety, 15 Mar. 2026

Leaf Home’s survey shows that among homeowners with basements, 58% have experienced water intrusion or moisture issues, yet many (62%) believe frozen pipes are the main culprit. —Jessica Safavimehr, Southern Living, 11 Mar. 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)