intruder
Uninvited house guest
An intruder is someone who enters a place without permission or welcome.
The word typically implies unwanted presence—a burglar in a home, a hacker in a computer system, or simply someone who shows up uninvited: The security system detected an intruder.
Intruder suggests violation of boundaries, whether physical, digital, or social.
Move with stealth
- prowlRoam stealthily
- creepStealthy, slow movement
- silentProducing no sound
- shadowLight blocked by object
undetected · hiding · lurking · covert · furtive · stealthy · evasion · concealed
One who steals
- robberOne who steals by force
- housebreakerOne who breaks in
- break-inUnlawful entry to premises
- burglaryIllegal entry to commit crime
robbery · heist · prowler · cat-burglar · safe-cracker · looter · pilferer · stolen
Not wanted here
- unwantedNot wished for
- gatecrasherUninvited event attendee
- outsiderOne excluded from group
- strangerPerson not yet known
unexpected · disruption · nuisance · privacy · violation · disturbance · interruption · imposition
Urgent warning signal
- sensorInput-detecting device
- motionChange in position
- surveillanceSystematic observation of subjects
- cameraImage capturing device
alert · monitoring · detector · flashing · siren · triggered · notification · response
sneak
Move with stealth
shadow · undetected · hiding · lurking · covert · furtive · stealthy · evasion · concealed · darkness
thief
One who steals
- robberOne who steals by force
- housebreakerOne who breaks in
- break-inUnlawful entry to premises
burglary · robbery · heist · prowler · cat-burglar · safe-cracker · looter · pilferer · stolen · loot
unwelcome
Not wanted here
- unwantedNot wished for
- gatecrasherUninvited event attendee
- outsiderOne excluded from group
stranger · unexpected · disruption · nuisance · privacy · violation · disturbance · interruption · imposition · crasher
alarm
Urgent warning signal
- sensorInput-detecting device
- motionChange in position
- surveillanceSystematic observation of subjects
camera · alert · monitoring · detector · flashing · siren · triggered · notification · response · perimeter
unauthorized
Not officially permitted
encroachment · poacher · squatter · private · land · fence · posted · warning · eviction · removal
danger
Exposure to harm
violent · confrontation · defense · weapon · attack · victim · fear · vulnerable · protect · security
- lawbreakersthief, robber, burglar, vandal, smuggler
- mysterious figuresenigma, phantom, shadowy figure, mysterious stranger, mystery man
- territorialityscent marking, marking, guarding, defending, border disputes
- trespassingtrespasser, criminal trespass, illegal entry, unlawful entry, no trespassing
- attackersaggressor, assailant, attacker, assaulter, ambusher
- intruderstrespasser, invader, burglar, prowler, infiltrator
intruderguest
Welcomed visitor
host · resident · rightful owner · occupant · tenant
- intruder alarmUnauthorized entry detector
- intruder drillPractice for unwelcome entry