S: (n) linesman (official (in tennis, soccer, football, etc.) who assists the referee in some way (especially by watching for out of bounds or offside))
S: (n) referee, ref ((sports) the chief official (as in boxing or American football) who is expected to ensure fair play)
W: (n) office [Related to: official] (an administrative unit of government) "the Central Intelligence Agency"; "the Census Bureau"; "Office of Management and Budget"; "Tennessee Valley Authority"