outrider
n. 骑马侍从,先驱者,摩托车警卫
Outriders are people such as policemen who ride on motorcycles or horses beside or in front of an official vehicle, in order to protect the people in the vehicle.
...a black Mercedes with motorcycle outriders provided by the city's police.
由该市警方的摩托护卫为其开道的黑色梅赛德斯车
1. an escort who rides ahead (as a member of the vanguard)