solder
n. C / Un. a metal mixture that you melt to join two metal pieces together. It is often used to fix electronics or pipes.
n. a fusible metal alloy used to create a permanent bond between metal workpieces. Often composed of lead and tin or lead-free alternatives, it has a melting point lower than that of the adjoining metals.
He used a hot iron to melt the solder onto the wire.
The technician noticed a crack in the solder on the circuit board, which was causing the device to lose power.
Modern electronics manufacturing has largely transitioned to lead-free solder to comply with environmental regulations, despite the higher melting temperatures required for a reliable joint.
From Middle English souder, soudere, soudur (noun), from Old French soldure, soudeure (noun), from Old French souder, solder (“to solder”, verb) (> Middle English souden (“to solder”)), from Latin solidāre (“make solid”).
Uncountable when referring to the material in general; countable when referring to specific types or alloys of the metal.