assistant referee
noun [ C ] uk/əˌsɪs.tənt ref.əˈriː/ us/əˌsɪs.tənt ref.əˈriː/
助理裁判员
in football, one of the two officials who help the referee to make decisions during a game
The assistant referee raised his flag for offside. 助理裁判员举旗示意越位。