outrider

1. N-COUNT Outriders are people such as police officers who ride on motorcycles or horses beside or in front of an official vehicle, in order to protect the people in the vehicle. 摩托衛隊; 護衛馬隊[usu n N]

...a black Mercedes with motorcycle outriders provided by the city's police. ...一輛黑色奔馳車和由該市警方提供的摩托衛隊。