You know this song, though you may not know it's origins!  There is a lot of lore around this song, written sometime in the 16th c. Some say Henry VIII wrote it for Anne Bolelyn. The lyrics have often been seen as a description of a "loose woman" . Green, at the time, was considered the dress color of prostitutes, because grass stains from rolling about in the grass, would be hidden! Over all, although people break it out for Christmas, this tune is considered a pagan tune, and a celebration of the witching women.