What does intrusion mean?
An intrusion is an unauthorized or unwelcome entry into a place, system, conversation, or private sphere. The word is especially common in discussions of privacy and security, where an intrusion may involve an intruder gaining access to private information, a building, or a restricted area. It can also mean an unwanted interruption, as in an intrusion into a discussion. The phrase 'prevent intrusion' reflects its frequent defensive use. In geology, an intrusion is a body of igneous rock created when magma forces its way through existing rock below the Earth's surface. The word derives from the Latin verb intrudere, meaning 'to force in.' Across its common and technical senses, intrusion conveys the crossing of a boundary, whether unwelcome or physically powerful enough to penetrate solid rock.
nounAn unauthorized or unwelcome entry into a place, space, activity, or sphere of privacy. In geology, it refers to a mass of magma that has forced its way through surrounding rock.
- An act of entering a place, system, conversation, or private sphere without authorization or welcome.
- A mass of igneous rock formed when magma intrudes into existing rock beneath the Earth's surface.
"The installation was designed to prevent any intrusion into the wildlife reserve."
"She objected to the intrusion of commercial messages into the program."
"The intrusion of magma into the surrounding rock created a new layer of igneous rock."
Used when referring to multiple acts of unauthorized entry, unwanted interruptions, or geological bodies formed by magma penetrating existing rock.
"The guards reported several intrusions into the compound during the night."
An intrusion is an unwanted arrival; in geology, it is magma crashing the party and forcing its way through rock.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does intrusion come from?
The noun comes through French from Medieval Latin intrusio, which was formed from Latin intrudere, 'to force in.' That verb combines the prefix in- with trudere, 'to push.' The related English words intrude, intrusive, and intrusion all reflect this history of pushing or forcing one's way in.
Related word forms
How intrusion is actually used
The word commonly has a negative or defensive connotation, especially when describing unwanted access to private, domestic, digital, or professional spaces. The geological sense is neutral technical terminology.
Easily confused with intrusion
An invasion usually involves entering and taking control of territory, whereas an intrusion is primarily an unauthorized or unwelcome entry.