This is the 971st most frequent Croatian word.
istri
"Istri" is the plural form of "Istrian," referring to people or things related to the Istria region in Croatia.
In this sentence, 'Istri' is the dative case of the place 'Istra', used here to indicate the location where someone lives.
Moj stric živi u Istri.
My uncle lives in Istria.
In this case, 'Istri' is the dative case of the noun 'Istra' being used to refer to my wife, reflecting a colloquial meaning.
Istri sam kupio poklon.
I bought a gift for my wife.
Here, 'Istri' is in the locative case, used to indicate the topic of discussion in conjunction with the preposition 'o' (about).