trigger
UK: ˈtrɪɡə | US: ˈtrɪɡər
n. a device that releases a mechanism (e.g., gun trigger)
vt. to cause an event or reaction
n. (psychology) a stimulus causing an emotional response
The word "trigger" originates from the Old Norse tregja, meaning "to pull or draw." It entered Middle English as trikker, referring to a mechanism that "pulls" or releases a device (e.g., a crossbow or gun). Over time, it expanded metaphorically to mean "initiating an event" (verb) and later, in psychology, "a stimulus provoking a response." The -er suffix denotes an agent or tool, reinforcing its mechanical roots.
He pulled the trigger, firing the gun.
The speech triggered widespread protests.
Loud noises are a trigger for her anxiety.
The alarm is triggered by motion sensors.
Avoid foods that might trigger allergies.