Security alarm trigger

• Trigger for booby trap
• Stumble, with anger — over this?
• Trigger on a trap
• Hidden explosives activator
• Hidden trigger
• Alarm trigger of a sort
• Triggering device

Wiktionary Word definitions in Wiktionary
n. 1 A cord or wire arranged so that when snagged or pulled by an intruder, it will trigger a detector or trap or a device, such as a land mine. 2 Any means of detecting intruders.

Wikipedia Word definitions in Wikipedia
A tripwire is a passive triggering mechanism. Typically, a wire or cord is attached to some device for detecting or reacting to physical movement. A tripwire may be a wire attached to one or more mines — normally bounding mines and the fragmentation type ...

Longman Dictionary of Contemporary English Word definitions in Longman Dictionary of Contemporary English
noun EXAMPLES FROM CORPUS ▪ Another edges his way towards him ... picking through mines and tripwires. ▪ At first they were detonated by cables or tripwires. ▪ Booby traps were usually small and frequently made out of a grenade, with a simple tripwire attached. ...