inˈtruder
B2Neutral, formal to informal. Common in news, legal, security, and computing contexts.
Definition
Meaning
A person or thing that enters a place or situation without permission, right, or invitation.
In computing, a program or unauthorized user that accesses a computer system; more broadly, anything that appears in a space or situation where it is not wanted or does not belong (e.g., an intrusive thought, a non-native species).
Linguistics
Semantic Notes
Core meaning centres on violation of boundaries (physical, digital, social). Always has negative connotations of being unwanted/unwelcome, though severity can vary (from trespasser to burglar to an unwelcome guest).
Dialectal Variation
British vs American Usage
Differences
No major differences in meaning or use. Spelling is identical. 'Home invader' is a more specific legal term used in US media.
Connotations
In both varieties, highly negative; implies threat, violation, or annoyance. In UK security contexts, 'intruder alarm' is the standard term.
Frequency
Slightly more frequent in UK English due to common phrases like 'intruder alarm' and media reports. In US, 'burglar' or 'trespasser' might be used more specifically in crime reporting.
Vocabulary
Collocations
Grammar
Valency Patterns
intruder + in/into + [place]intruder + on/upon + [situation/rights]intruder + from + [origin]Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “an intruder on the peace”
- “feel like an intruder”
Usage
Context Usage
Business
Refers to unauthorized personnel in a secure area or unauthorized access to data/networks.
Academic
Used in sociology (social boundaries), ecology (invasive species), law (trespass), and computer science.
Everyday
Someone who enters your home/garden without permission; an unwelcome person at a private event.
Technical
In cybersecurity, a malicious actor or program that gains unauthorized access to a network or system.
Examples
By Part of Speech
verb
British English
- The cat seemed to intrude upon their private moment.
- I don't wish to intrude, but may I ask a question?
American English
- New regulations intrude on personal freedoms.
- Sorry to intrude, but your meeting time is up.
adverb
British English
- He glanced at her intrusively.
- The fence was built intrusively on the property line.
American English
- The light shone intrusively into the room.
- She questioned him intrusively about his finances.
adjective
British English
- The intrusive questions made her uncomfortable.
- They installed an intrusive surveillance system.
American English
- The intrusive media coverage was relentless.
- The software was flagged for intrusive data collection.
Examples
By CEFR Level
- The dog barked at the intruder in the garden.
- An intruder alarm is good for safety.
- She felt like an intruder at the family party.
- The security light comes on if an intruder is detected.
- The court charged him as an intruder for entering the construction site.
- The new software acts as a firewall against digital intruders.
- The journalist was accused of being an intruder upon the grief of the victim's family.
- In ecological terms, the non-native mussel is a destructive intruder in the river system.
Learning
Memory Aids
Mnemonic
Think of 'IN TRUDER' as someone who TRUDES IN (a made-up verb for 'pushes in rudely').
Conceptual Metaphor
PRIVACY/SPACE IS A CONTAINER; an intruder is someone who breaks into that container.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid direct cognate 'интрудер' (very rare/technical). Use 'нарушитель' (boundary violator), 'злоумышленник' (malicious person), or 'незваный гость' (uninvited guest) depending on context.
Common Mistakes
- Confusing 'intruder' (person/thing) with 'intrusion' (the act). Incorrect: 'He committed an intruder.' Correct: 'He was an intruder.' / 'He committed an intrusion.'
Practice
Quiz
In which context is 'intruder' LEAST likely to be used?
FAQ
Frequently Asked Questions
No. While most commonly a person, it can refer to animals, objects, ideas, or software that enters an area without welcome (e.g., 'The fox was an intruder in the hen house,' 'The pop-up ad was a digital intruder').
They are often synonyms. 'Trespasser' is more strictly legal, implying violation of property law. 'Intruder' is broader, covering social, digital, and personal spaces where no specific law may be broken (e.g., intruding on a conversation).
Almost never. Its core semantic feature is being unwanted or unwelcome. Even in neutral use ('I felt like an intruder'), it describes a subjective negative feeling of not belonging.
The verb is 'to intrude' (intruded, intruding). It means to put oneself into a place or situation where one is not welcome or invited. Common patterns: 'intrude into a room,' 'intrude on/upon someone's privacy/time.'