any of various alloys fused and applied to the joint between metal objects to unite them without heating the objects to the melting point.
anything that joins or unites: the solder of their common cause.

verb (used with object)

verb (used without object)

to unite things with solder.
to become soldered or united; grow together.

Origin of solder

1325–75; (noun) Middle English soudour < Old French soudure, soldure, derivative of solder to solder < Latin solidāre to make solid, equivalent to solid(us) solid + -āre infinitive suffix; (v.) late Middle English, derivative of the noun
Related formssol·der·a·ble, adjectivesol·der·er, nounsol·der·less, adjectivede·sol·der, verb (used with object)re·sol·der, verb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for solder

Contemporary Examples of solder

Historical Examples of solder

  • One end of the barrel is placed in this hole and held with a drop of solder.

    Boys' Book of Model Boats

    Raymond Francis Yates

  • The shield is forced over the barrel and held in place with a drop of solder.

    Boys' Book of Model Boats

    Raymond Francis Yates

  • Solder is flowed around the pivot to hold it securely in place.

    Boys' Book of Model Boats

    Raymond Francis Yates

  • The one political idea of his life was to solder Italy firmly to Germany.

    England and Germany

    Emile Joseph Dillon

  • One is the ordinary tinman's solder composed of lead and tin.

    On Laboratory Arts

    Richard Threlfall

British Dictionary definitions for solder



an alloy for joining two metal surfaces by melting the alloy so that it forms a thin layer between the surfaces. Soft solders are alloys of lead and tin; brazing solders are alloys of copper and zinc
something that joins things together firmly; a bond


to join or mend or be joined or mended with or as if with solder
Derived Formssolderable, adjectivesolderer, noun

Word Origin for solder

C14: via Old French from Latin solidāre to strengthen, from solidus solid
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for solder

mid-14c., sawd "mend by soldering," from solder (n.). Modern form is a re-Latinization from early 15c. Related: Soldered; soldering.


early 14c., soudur, from Old French soldure, soudeure, from souder, originally solder, "to consolidate, close, fasten together, join with solder" (13c.), from Latin solidare "to make solid," from solidus "solid" (see solid (adj.)).

Modern form in English is a re-Latinization from early 15c. The loss of Latin -l- in that position on the way to Old French is regular, e.g. poudre from pulverem, cou from collum, chaud from calidus. The -l- typically is sounded in British English but not in American, according to OED, but cf. Fowler, who wrote that solder without the "l" was "The only pronunciation I have ever heard, except from the half-educated to whom spelling is a final court of appeal ..." and was baffled by the OED's statement that it was American. Related: Soldered; soldering. The noun is first attested late 14c.

Online Etymology Dictionary, © 2010 Douglas Harper