tripwire

/trip-wahyuhr/US // ˈtrɪpˌwaɪər //UK // (ˈtrɪpˌwaɪə) //

绊线,绊网,绊脚石,绊马索

Definitions

n.名词 noun

1
- : a wire used to set off concealed explosives, as one stretched across a footpath to be struck and activated by the foot of an enemy soldier.
- : a wire that activates a trap, camera, or other device when stepped on, tripped on, or otherwise disturbed.

The tripwire for an unfolding plot to take control of the flight would be the transponder, operated by a switch beside the pilots.
The transponder is really the tripwire for whatever began to unfold on that jet.
The emotions of Democrats are on a tripwire, ready to react at the slightest provocation.