intrusion

intrusion — noun

1. a situation in which a person's private space, time, or affairs are entered or a

1.nounB2
Definition

a situation in which a person's private space, time, or affairs are entered or affected without their permission, making them feel uncomfortable or annoyed.

Example

The reporter's questions were an unwanted intrusion into Yan's family life.

intrusion into + [abstract domain] — unwanted boundary crossing

Maeve apologised for the intrusion after she walked into the meeting by mistake.

apologise for + the intrusion — polite formula for unexpected entry

Common collocations
  • unwanted intrusion
  • rude intrusion
  • personal intrusion
  • intrusion into someone's privacy
  • intrusion on someone's time
  • an intrusion upon
Synonyms
  • invasion

    stronger and more aggressive; often implies hostile or military force

  • encroachment

    suggests a gradual or subtle overstepping of boundaries, especially of rights or territory

  • interruption

    milder; focuses on a temporary break in an activity rather than a violation of space or rights

Antonyms
  • respect

    showing consideration for someone's privacy, space, or time

  • welcome

    an invitation or open reception, the opposite of unwanted entry

Grammar Patterns

intrusion + into + [place/domain]

intrusion + on/upon + [possession/right]

an intrusion — countable form

Usage Note

Frequently used with the prepositions 'into' (intrusion into a space) or 'on/upon' (intrusion on someone's time or privacy). The countable form 'an intrusion' is common when referring to a single event; the uncountable form is preferred when discussing the concept in general ('intrusion of any kind is not allowed').

Common Mistakes

The loud music was an intrusion for my sleep.
The loud music was an intrusion on my sleep.
The correct preposition when specifying what is affected is 'on', not 'for'.
I felt intrusion when he entered.
I felt it was an intrusion when he entered.
When referring to a specific event, the countable form 'an intrusion' is usually needed.

2. in geology, the movement of hot liquid rock from deep underground into cracks or

2.nounC1
Definition

in geology, the movement of hot liquid rock from deep underground into cracks or between layers of older rock that were already in place.

Example

This mountain's granite formed through a magma intrusion millions of years ago.

passive + intrusion of magma — geological formation process

Samir the geologist pointed to a dark volcanic intrusion visible in the cliff face.

Common collocations
  • magma intrusion
  • volcanic intrusion
  • igneous intrusion
  • ancient intrusion
  • granite intrusion
Synonyms
  • injection

    sometimes used in geology to describe magma forced into cracks, but less common than intrusion

  • penetration

    describes the act of pushing through; broader and not geology-specific

Grammar Patterns

intrusion + of + [rock type]

intrusion + into/between + [rock formation]

Usage Note

A technical term in geology and earth science. Most commonly encountered in academic papers, textbooks, and documentary commentary rather than everyday conversation. The uncountable form ('intrusion of magma') is favoured when describing the process; the countable form ('a large intrusion') refers to a specific body of rock that formed this way.

Word family

  • intrude
    verbB2
  • intruder
    nounB2
  • intrusive
    adjectiveB2
  • intrusively
    adverbC1
  • intrusiveness
    nounC1

Synonym discussion

Sense: noun/1

Intrusion, invasion, encroachment, and interruption all describe some form of unwanted entry, but they differ in intensity and scope. Intrusion is the broadest term, covering any unwanted entry into a space, conversation, or situation. Invasion implies a forceful, often hostile entry — a newspaper might call a journalist's relentless questioning 'an invasion of privacy,' which feels more aggressive than an intrusion. Encroachment suggests a gradual, creeping advance over boundaries, commonly used in legal or territorial contexts: 'the factory's encroachment on protected wetlands.' Interruption is the mildest, focusing on a temporary break in an activity: 'a phone call interruption during a meeting.' In everyday speech, interruption and intrusion overlap, but intrusion carries a stronger sense of boundary violation.

invasionencroachmentinterruption

Common collocations

Nouns

  • privacy
  • space
  • time
  • territory
  • magma
  • rock

Adverbs

  • unwelcome
  • unwanted
  • minor
  • major
  • serious

Phrases

  • act of intrusion
  • form of intrusion
  • without intrusion

Prepositions

  • into
  • on
  • upon
  • of

Etymology

LatinFrenchEnglish

Intrusion comes from the Latin verb 'intrudere', meaning 'to thrust in' — a combination of the prefix 'in-' (in) and 'trudere' (to thrust or push). It passed through Old French ('intrusion') before entering English in the late Middle Ages. The geological sense, describing how molten rock forces its way into existing rock layers, developed in the early 1800s as the field of geology advanced.