What Is the Etymological Origin of the Word 'Salt'?
"Salt was a key element in the diet of our Indo-European ancestors, and their word for it, *sal-, is the source of virtually all the modern European terms, including Russian sol, Polish sol, Serbo-Croat so, Irish salann, and Welsh halen. Greek hals has given English halogen. And Latin sal, besides evolving into French sel, Italian sale, Spanish sal, and Rumanian sare, has contributed an enormous range of vocabulary to English, including salad, salary, saline, sauce, saucer, and sausage. Its Germanic descendant was *salt-, which has produced Swedish, Danish, and English salt and Dutch zout, and also lies behind English silt and souse."
~ John Ayto’s “Dictionary of Word Origins”