Nouns

(n)referee, ref(sports) the chief official (as in boxing or American football) who is expected to ensure fair play
(n)reviewer, referee, readersomeone who reads manuscripts and judges their suitability for publication
(n)refereean attorney appointed by a court to investigate and report on a case

Verbs

(v)referee, umpirebe a referee or umpire in a sports competition
(v)referee, peer reviewevaluate professionally a colleague's work