referee’s assistant
noun/ˌrefəriːz əˈsɪstənt/
/ˌrefəriːz əˈsɪstənt/
(also assistant referee)
- (in football (soccer)) the official name for a linesman (= an official who helps the referee, for example in deciding whether or where a ball has passed outside the field of play)
助理裁判（边线裁判员的正式名称）