assistant referee
US /əˌsɪs.tənt ˈref.ə.ri/
UK /əˌsɪs.tənt ˈref.ə.ri/

1.
árbitro assistente, bandeirinha
an official who assists the referee in a soccer match, typically by indicating when the ball is out of play or when a player is offside
:
•
The assistant referee raised the flag for offside.
O árbitro assistente levantou a bandeira para impedimento.
•
The decision was confirmed by the assistant referee.
A decisão foi confirmada pelo árbitro assistente.