soda, lye, sodium hydroxide (NaOH) / sodium (Na) / sodium carbonate (Na₂CO₃) / seepweed, sea blite, saltwort (plants, usually of the genus Suaeda, which produce sodium carbonate when burned) / prickly saltwort (Salsola kali, syn. Kali turgidum)

caustic soda, lye

baking soda, sodium bicarbonate

to solder

welding machine

welder

plural of soudeur

feminine plural of soudeur

first-person singular simple future of souder

second-person singular present indicative/subjunctive of souder