Doppelgangers (4,7)
(Other definitions for dead ringers that I've seen before include "no longer in the belfry?" , "Very similar-looking people" , "doubles" , "Identical twins" , "BBC programme" .)
(Other definitions for doubles that I've seen before include "match in court" , "sort of game" , "Made twice as much" , "Tennis match for four players" , "Like Carton and Darnay" .)