Tennis, Soccer, etc. a female official who has the responsibility to make decisions along a sideline, goal line, etc., as in reporting whether the ball is inside or outside the line
See lineswoman in American Heritage Dictionary 4
noun Sports
A woman official in various court games whose chief duty is to call shots that fall out of bounds.
Either of two women officials in ice hockey who call icing and offsides, conduct face-offs, and call penalties.