This is the 2435th most frequent Polish word.
austrii
The word "Austrii" in Polish means "of Austria" or relates to Austria in the genitive or locative case.
Here, 'Austrię' is the accusative case of 'Austria' because it is the direct object of the sentence, indicating the country we visited.
W zeszłym roku odwiedziliśmy Austrię.
Last year, we visited Austria.
In this sentence, 'Austrii' is in the locative case, used after prepositions indicating location, such as 'in'.
Cieszę się, że widziałem Alpy w Austrii.
I am glad I saw the Alps in Austria.
Here, 'Austrii' is in the genitive case, showing possession or association with the noun 'mieszkaniec' (inhabitant).