noun

1. a metal alloy that is heated and used to join or patch metal parts or surfaces: soft solders of tin-lead alloys melt easily; hard (or brazing) solders of copper-zinc alloys melt only at red heat
2. anything that joins or fuses; bond

Etymology: ME soudre < OFr souldure < soulder, to make solid < L solidare < solidus, solid

transitive verb

1. to join, patch, etc. with solder
2. to act as a bond between; unite

intransitive verb

1. to become joined or united as by solder
2. to join things with solder