Solder

A metal or metallic alloy used when melted for uniting adjacent metallic edges or surfaces; a metallic cement.

anything which unites or cements.

To unite (metallic surfaces or edges) by the intervention of a more fusible metal or metallic alloy applied when melted; to join by means of metallic cement.

To mend; to patch up.

an alloy (usually of lead and tin) used when melted to join two metal surfaces