When you weld two pieces of metal together using a torch, this is an example of when you fuse.
When you overload the circuit in your house by turning on too many different appliances at once and your power to the appliances you are using shuts off, the electrical device that tripped and caused the power to stop to the overloaded circuit is an example of a fuse.
The little string sticking out of a bomb that you light in order to get the bomb to go off is an example of a fuse.
Bits of glass fused in a kiln; atomic nuclei that are fused together inside the stars.
When talking about being laid off, he has a short fuse.