Definitions for safety fuse
a slow-burning fuse consisting of a tube or cord filled or saturated with combustible matter; used to ignite detonators from a distance
fuse, electrical fuse, safety fuse(noun)
an electrical device that can interrupt the flow of electrical current when it is overloaded
The Standard Electrical Dictionary
A strip of metal inserted so as to form part of a circuit and of such size that a smaller current [than] would heat the regular wire of the circuit dangerously, so as to cause a conflagration for instance, would melt the fuse and open the circuit. As it sometimes happens that a safety fuse melts without parting a weight is sometimes hung upon it, so as to break it as it softens.