This is the 14040th most frequent Polish word.
powiatowym
"Powiatowym" means "county" or "district-level" (adjective, relating to a powiat in Poland).
The term 'powiatowego' describes the noun 'starostwa', indicating it pertains to a county-level administrative office.
Zatrzymaliśmy się w budynku starostwa powiatowego.
We stopped at the office building of the county authority.
Here, 'powiatowa' is the feminine form of the adjective, describing the noun 'droga' as being related to a 'powiat' or county.
Nowa droga powiatowa została ukończona w zeszłym miesiącu.
The new county road was completed last month.
In this case, 'Powiatowy' functions as an adjective, modifying the noun 'plan', indicating a development plan of the county.