linesman
/ˈlaɪnzmən; `laɪnzmən/ (also esp US lineman / ˈlaɪnmən; `laɪnmən/) n (pl -men / -mən;-mən/)
1 official helping the referee in certain games, esp in deciding whether or where a ball crosses one of the lines 边线裁判员; 巡边员; 司线员.
2 person whose job is to repair and maintain electrical or telephone lines 线务员, 架线工（维修供电或电话线路者）.