1. (

• trip ,
• actuate ,
• trigger ,
• activate ,
• set_off ,
• spark_off ,
• spark ,
• trigger_off ,
• touch_off

) put in motion or move to act; "trigger a reaction"; "actuate the circuits" ;

2. (

• spark ,
• sparkle ,

) emit or produce sparks; "A high tension wire, brought down by a storm, can continue to spark" ;