double:
(plural: ‘doubles‘; for the right pronunciation of this word, please click here)

an actress and her double (guess who’s who?)
a person who does difficult or dangerous activities (scenes) for an actor or actress in film making, — a substitute;
a person (or thing) that looks exactly or closely like another person (or thing);
a counterpart; a lookalike; a ringer;
an actor who plays two characters in one play (drama) or film/movie, like identical twins or clones,

several alleged ‘doubles’ of Saddam Husien, the late Iraqi President
A stunt or body double is a stunt man or woman who, without showing his or her face, acts in place of the real actor in fighting scenes.
Mary is the double of her cousin Martha; people find it hard to tell who’s Mary and who’s Martha.
Most actors and actresses play doubles, at least in one action film, including actors such as Swazinigger and Van Dame.
It’s rumoured that Winston Churchill of UK, Hitler of Germany, Saddam Hussein of Iraq had several doubles who posed as the real ones in public meetings for security reasons, i.e. if any attempt on their lives had been made, it was the double that would be harmed but not the real one!
