umpire vs third party

umpire and third party both are nouns.

Word	Noun	Adjective	Verb	Adverb
umpire	Yes	No	Yes	No
third party	Yes	No	No	No

As nouns, third party is a hyponym of umpire; that is, third party is a word with a more specific, narrower meaning than umpire:

umpire: someone chosen to judge and decide a disputed issue
third party: someone other than the principals who are involved in a transaction

umpire (noun)	third party (noun)
an official at a baseball game	a political party organized in opposition to the major parties in a two-party system
someone chosen to judge and decide a disputed issue	someone other than the principals who are involved in a transaction

umpire (verb)	third party (verb)
be a referee or umpire in a sports competition