A doppelgänger or doppelga(e)nger (/ˈdɒpəlˌɡɛŋər/ or /-ˌɡæŋər/; German: [ˈdɔpl̩ˌɡɛŋɐ], literally "double-goer") is a look-alike or double of a living person, sometimes portrayed as a paranormal phenomenon, usually seen as a of bad luck. In other traditions and stories, they recognize one's 'double-goer' as an evil twin. Doppelgänger is a German word. In modern times, the term twin stranger is occasionally used.
The word "doppelgänger" is often used in a more general sense to describe any person who physically or behaviorally resembles another person.
The word doppelgänger is a loanword from the German Doppelgänger, consisting of the two substantives Doppel (double) Gänger (walker or goer). The singular and plural forms are the same in German, but English usually prefers the plural "doppelgängers." It was first used by Jean Paul in the novel Siebenkäs (1796), and his newly coined word is explained by a footnote.
As is true for all other nouns in German, the word is written with an initial capital letter. In English, the word should be uncapitalized (doppelgänger). It is also common to drop the diacritic umlaut, writing "doppelganger."