Sol·der n. A metal or metallic alloy used when melted for uniting adjacent metallic edges or surfaces; a metallic cement. Hence, anything which unites or cements.
Hard solder, a solder which fuses only at a red heat, as one composed of zinc and copper, or silver and copper, etc.
Soft solder, a solder fusible at comparatively low temperatures; as, plumbers' solder, consisting of two parts lead and one part tin, is a soft solder.
Sol·der, v. t. [imp. & p. p. Soldered p. pr. & vb. n. Soldering.]
1. 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.
2. To mend; to patch up. “To solder up a broken cause.”
n : an alloy (usually of lead and tin) used when melted to join
two metal surfaces
v : join or fuse with solder; "solder these two pipes together"