By ESC"Seventeenth-century Frenchmen, Italians, and Englishmen generally employed a variant of the Latin 'silvaticus,' meaning a forest inhabitant or man of the woods, for the Indian as the earlier spellings of 'saulvage,' 'salvaticho,' and 'salvage' show so well in each of the respective languages. English usage switched from 'savage' to 'Indian' as the general term for Native Americans in the seventeenth century, but the French continued to use 'sauvage' as the preferred word into the nineteenth century. The original image behind this terminology probably derives from the ancient one associated with the 'wild man,' or 'wilder Mann' in Germany."An online dictionary confirms this:
savage1250-1300; Middle English savage, sauvage (adj.) < Middle French sauvage, salvage < Medieval Latin salvāticus, for Latin silvāticus, equivalent to silv (a) woods + -āticus adj. suffixComment: So "savage" the adjective came from the same root as "sylvan" and meant "of the woods." Interesting.