- Football An official who marks the downs and the position of the ball and watches for certain violations from the sidelines.
- Sports An official in various court games whose chief duty is to call shots that fall out of bounds.
- Sports An official in soccer and other field games who indicates when the ball has gone out of bounds.
- Sports Either of two officials in ice hockey who call icing and offsides, conduct face-offs, and call penalities.
- See lineman.