sylvan (adj.)
"of the woods," 1570s, from Middle French sylvain (1530s), from Latin silvanus "pertaining to wood or forest" (originally only in silvanae "goddesses of the woods"), from silva "wood, woodland, forest, orchard, grove," of unknown origin. The unetymological -y- is a misspelling in Latin from influence of Greek hyle "forest," from which the Latin word formerly was supposed to derive.