solder
Definitions
A low-melting alloy, especially one based on lead and tin, used for joining metal surfaces.
To join or fuse metal parts together by melting and applying a solder.
Examples
You need to use a hot iron to melt the solder and join the two wires together.
The technician carefully applied solder to the circuit board to repair the loose connection.
He had to solder the broken metal joint back into place to fix the antique lamp.