third party vs umpire

third party and umpire both are nouns.

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

As nouns, umpire is a hypernym of third party; that is, umpire is a word with a broader meaning than third party:

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

Other hypernyms of third party include arbiter, arbitrator.

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

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