linesman

An official who marks the downs and the position of the ball and watches for certain violations from the sidelines.

An official in various court games whose chief duty is to call shots that fall out of bounds.

An official in soccer and other field games who indicates when the ball has gone out of bounds.

Either of two officials in ice hockey who call icing and offsides, conduct face-offs, and call penalities.

Milit., a private in the line; an infantryman.

In Amer. foot-ball, one of the forwards; also, the man who has charge of the measurements of the distance gained and assists the umpire in various ways.

A workman engaged in the erection or maintenance of the line-wires of a telegraphic or telephonic system, or of electric circuits of any sort.

the official (in tennis or soccer) who watches the lines.