\Sol"der\, n. [Formerly soder; F. soudure, OF. soudeure,
fr. OF. & F. souder to solder, L. solidare to fasten, to make
solid. See {Solid}, and cf. {Sawder}.]
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}.] [Formerlysoder. See {Solder}, n.]
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.''
   --Hooker.