Collocations for referee - noun

basketball, boxing, football, soccer (esp. AmE), etc.
match (esp. BrE), meet (AmE), tournament
decisions taken by the tournament referee

international
top
professional (esp. BrE)
my 20 years as a professional referee

assistant (in football/soccer)
an assistant referee flagged for a penalty

guest (esp. AmE)
He was acting as a guest referee in the main wrestling event.

award sb sth
The referee awarded a free kick to the home team.

blow his/her/the whistle
stop sth
book sb, send sb off (both in football/soccer)
The referee booked three players for offensive behaviour.

the referee's decision

academic

act as, be

referee for
His former employer agreed to act as a referee for him.