Spear carrier
A spear carrier is a nickname for a minor acting part. It generally pertains to a character that appears in several scenes, but mostly in the background.
In the world of Opera, the term is sometimes used literally: When a male chorus is required, as in Aida, for example, the onstage "army", armed with spears or swords, usually consists of several singers and as many who remain silent, filling out the group. The silent ones are known as spear carriers, to differentiate them from the male chorus members.