Extra
1. A background actor or extra is a performer in a film, television show, stage, musical, opera or ballet production, who appears in a nonspeaking, nonsinging or nondancing capacity, usually in the background (for example, in an audience or busy street scene). War films and epic films often employ background actors in large numbers: some films have featured hundreds or even thousands of paid background actors…On a film or TV set, background actors are usually referred to as “background performers”, “background artists” or simply “background” while the term “extra” is rarely used.
Source: Wikipedia