tripwire
Stretched ground sensor
A tripwire is a wire stretched close to the ground that triggers something when disturbed—originally a trap or alarm, now often an explosive device.
Figuratively, a tripwire is any mechanism designed to detect or trigger action at a threshold: The spending cap serves as a tripwire for budget negotiations.
A tripwire force is a small military deployment meant to guarantee larger involvement if attacked.
Hidden device to harm
- landmineBuried pressure-activated explosive
- IEDMakeshift explosive weapon
- minefieldExplosive-laden territory
- detonatorExplosive initiation device
explosive · ambush · claymore · grenade · pressure plate · perimeter defense · snare · guerrilla
What initiates action
- catalystAgent enabling change
- thresholdPoint of beginning
- red flagIndicator of danger
- warning signIndicator of potential danger
tipping point · flashpoint · provocation · escalation · activation · precipitant · spark · fuse
Urgent warning signal
- sensorInput-detecting device
- detectorDevice that senses
- breachBreaking of agreement
- intrusionUnauthorized entry into space
perimeter · monitoring · alert · activation · circuit · laser beam · infrared · motion sensor
booby trap
Hidden device to harm
- landmineBuried pressure-activated explosive
- IEDMakeshift explosive weapon
- minefieldExplosive-laden territory
detonator · explosive · ambush · claymore · grenade · pressure plate · perimeter defense · snare · guerrilla · trench
trigger
What initiates action
warning sign · tipping point · flashpoint · provocation · escalation · activation · precipitant · spark · fuse · boundary
alarm
Urgent warning signal
intrusion · perimeter · monitoring · alert · activation · circuit · laser beam · infrared · motion sensor · entry point
cord
Flexible twisted strand
taut · concealed · hidden · stretched · snag · catch · pull · release · spring-loaded · mechanism
- weaponsknife, gun, sword, swords, rifle
- deterrentsguard dog, warning, security camera, penalty, padlock
- trapstrap, bear trap, mousetrap, rat trap, ant trap
- warningswarning, alert, caution, danger, warning sign
- pitfallspitfall, trap, snare, catch, snag
- ambushambuscade, bushwhack, sneak attack, surprise attack, trap
tripwiremotion sensor
Device detecting nearby activity
radar · thermal imaging · infrared sensor · sonar · remote sensing
tripwirepush button
Depressible control element
remote control · safety switch · remote detonator · dead man's switch · kill switch
tripwirewarning sign
Indicator of potential danger
caution tape · barrier · fence · flashing light · ultimatum