county vs territorial division

county and territorial division both are nouns.

Word	Noun	Adjective	Verb	Adverb
county	Yes	No	No	No
territorial division	Yes	No	No	No

As nouns, territorial division is a hypernym of county; that is, territorial division is a word with a broader meaning than county:

Other hypernyms of county include administrative district, administrative division.

county (noun)	territorial division (noun)
(United Kingdom) a region created by territorial division for the purpose of local government	a district defined for administrative purposes
(United States) the largest administrative district within a state