fuse

fuse 1

•  noun [C]

1    a short wire inside a piece of electrical equipment that melts if too much electricity passes through it:

?The fuse has blown. (= it has melted and stopped the electrical equipment from working)
2    a part that is connected to a bomb, FIREWORK etc, that delays or starts the explosion


fuse 2

• verb [I,T]

1    to join together and become one thing, or to join two things together:
?The bones of the spine had become fused together.
2    BrE if an electrical system fuses, or if you fuse it, it stops working because the fuse has melted:
?The lights had fused.