walk–on 
/ˈwɑ:kˌɑ:n/ noun
plural walk–ons /ˈwɑ:kˌɑ:n/ noun [count] 1 : a minor part in a play or movie
▪ a walk-on part/role 2 US : a college athlete who tries to become a member of an athletic team without having been asked to join or given a scholarship
▪ a walk-on part/role
