wraith

If you see your own double, you're in trouble, at least if you believe old superstitions. The belief that a ghostly twin's appearance portends death is one common to many cultures. In German folklore, such an apparition is called a Doppelgänger (literally, "double goer"); in Scottish lore, they are wraiths. The exact origin of the word wraith is misty, however, and etymologists can only trace it back to the early 16th century—in particular to a 1513 translation of Virgil's Aeneid by Gavin Douglas (the Scotsman used wraith to name apparitions of both the dead and the living). In current English, wraith has taken on additional, less spooky, meanings; it now often suggests a shadowy—but not necessarily scary—lack of substance.