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: (adj) unofficial [Opposed to: official] (not having official authority or sanction) "a sort of unofficial mayor"; "an unofficial estimate"; "he participated in an unofficial capacity"
S: (adj) unofficial (not having official authority or sanction) "a sort of unofficial mayor"; "an unofficial estimate"; "he participated in an unofficial capacity"