referee vs umpire

referee and umpire both are nouns.

Word	Noun	Adjective	Verb	Adverb
referee	Yes	No	Yes	No
umpire	Yes	No	Yes	No

As verbs, referee and umpire are synonyms defined as:

referee (noun)	umpire (noun)
(sports) the chief official (as in boxing or American football) who is expected to ensure fair play	an official at a baseball game
someone who reads manuscripts and judges their suitability for publication	someone chosen to judge and decide a disputed issue
an attorney appointed by a court to investigate and report on a case

referee (verb)	umpire (verb)
evaluate professionally a colleague's work	be a referee or umpire in a sports competition
be a referee or umpire in a sports competition