A doppelgänger (/ˈdɒpəlɡɛŋər, -ɡæŋər/), doppelgaenger or doppelganger is a biologically unrelated look-alike, or a double, of a living person. In fiction and mythology, a doppelgänger is often portrayed as a ghostly or paranormal phenomenon and usually seen as a harbinger of bad luck. Other traditions and stories equate a doppelgänger with an evil twin. In modern times, the term twin stranger is occasionally used. The word "doppelgänger" is often used in a more general and neutral sense, and in slang, to describe any person who physically resembles another person.