Correct spelling for the English word "souder" is [sˈa͡ʊdə], [sˈaʊdə], [s_ˈaʊ_d_ə] (IPA phonetic alphabet).
The etymology of the word "souder" can be traced back to the Old English word "sūdor", which means "solder" or "metal alloy". This term was derived from the Old French word "souder", meaning "to join together" or "to solder". The Old French word, in turn, comes from the Latin word "solidāre", meaning "to make solid", which is derived from "solidus", meaning "solid" or "firm". The term "souder" has been used in English since the 14th century to refer to the process of joining or bonding metals using solder.