(a device with) a thin wire which melts and breaks the circuit when the electric current is too strong

meld, intermix

(to cause systems, e.g. for travel) to link together

blend, unite; contrive

to make (an article of clothing etc) by looping wool etc on long needles

intertwine

(to cause business companies) to become one unit; to fade or change gradually into something

bring or come together

to mix (things)

physically join

a variety of substances put together for a purpose; a group of different kinds (of people)

combine, join

to make (threads) into cloth etc; make (cloth etc) from threads

blend, unite; contrive

of weave

blend, unite; contrive