IPA: /ˈtrɪpˌwaɪə/
KK: /ˈtrɪpˌwaɪər/
A wire or line that is set up to activate a trap or device when someone or something touches it.
The soldiers set up a tripwire to alert them of any intruders.
Tripwire → The word is formed from "trip" (from Old English *tryppan*, meaning to stumble or fall) and "wire" (from Old English *wir*, meaning a thin, flexible strand of metal). The term "tripwire" refers to a wire that, when tripped over, causes a mechanism to activate, often used in traps or alarms.
Imagine a wire that causes someone to 'stumble' ('trip') when they accidentally step on it — that's how a tripwire works.
No commonly confused words.