fuse
n. countablen. a small safety part in an electrical device that breaks the flow of power if it gets too high. It can also mean a string or wire used to light an explosive.
n. a safety device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level; alternatively, a cord or tube used to ignite an explosive charge.
The lights went out because a fuse blew in the kitchen.
The electrician replaced the blown fuse to restore power to the entire upstairs floor safely.
Before the demolition team could proceed with the controlled explosion, they had to ensure the fuse was long enough to allow everyone to reach a safe distance.
Often used with the verb 'blow' to describe a circuit failure or 'light' when referring to explosives.