 As Tolkien admitted in a letter to his son, Shelob "is of course only 'she + lob, "lob" being an archaic English word for spider, influenced by Old English "loppe" or "spider".The word is not related to "cob" nor "cobweb".Old English "attercoppe" (meaning "spider") is derived from "atter" meaning "poison" and "coppe" meaning "head"; the OE term is a loan from Old Norse language and survives in modern Danish as "edderkop", spider.