Where does “souder” come from?
souder (English) comes from Old French soldoier, from Old French solde, from Latin solidus, from Proto-Italic soliðos, from Proto-Indo-European solh₂-i-dʰ-o-s, from Proto-Indo-European solh₂- — whole.
Ancestry of “souder”, step by step
souder traces back through two separate lines of ancestry.