English Reference
noun · verb

solder

n. · v.
US /ˈsɑdɝ/ UK /sˈɒldɐ/ sol·der UK spelling soldering, solders

  1. 01 B2 Upper Intermediate Technical Technical

    n.a soft metal that melts easily, used to join wires or metal parts together.

    n.a fusible metal alloy, traditionally composed of tin and lead, used to create a permanent bond between metal workpieces.

    Simple

    He used a small amount of solder to fix the broken wire on the circuit board.

    In context

    The technician applied the solder precisely to the joint, ensuring a reliable electrical connection without damaging the surrounding components.

    alloyfiller metal
  2. 02 B2 Upper Intermediate Technical Technical

    v.to join two pieces of metal by melting a soft metal onto them.

    v.to join or mend metal objects by applying a molten alloy with a lower melting point than the workpieces.

    Simple

    You need to solder these two wires together to complete the circuit.

    In context

    After cleaning the copper pipes, the plumber began to solder the joints to prevent any future leaks in the system.

    Usage

    The verb is transitive and requires a direct object, often the parts being joined.

    desolderdetach
  3. 03 C1 Advanced Literary

    v.to join two things or people together very strongly, like they are one piece.

    v.to unite or bond things or people closely and firmly as if by the use of solder.

    Simple

    The shared experience of the war helped solder the two nations together.

    In context

    Years of collaborative research had served to solder their professional relationship into a formidable partnership that dominated the field.

I’d never done it before, but the seven-segment display had to be soldered to its backpack board, so I grabbed a baby’s-first-soldering-iron kit from Amazon and a roll of 60/40 solder.

Ars Technica· 23 Jul 2026

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”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin solidō
Level C1 · Advanced
Frequency Occasional
Updated