Fuse wire is a wire of

A fuse is a safety device connected in series with the circuit. It must melt and break the circuit when the current exceeds a safe value.
High resistance (per unit length): more heat is produced in it ($H = I^2Rt$), so it heats up quickly when the current increases.
Low melting point: it melts easily at that moderately high temperature, before the appliance or wiring is damaged.
A fuse wire is usually an alloy of tin and lead.
So fuse wire is a wire of high resistance and low melting point.