This is the 235th most frequent Croatian word.
starije
"Starije" means "older" in English.
Here, 'starija' is an adjective used to describe 'sister', indicating that she is older in age compared to another sibling.
Njegova starija sestra igra klavir.
His older sister plays the piano.
In this sentence, 'starijoj' is the feminine, dative case form of 'starija', used to describe the building as older.
Stan u starijoj zgradi zahtijeva renovaciju.
The apartment in the older building requires renovation.
'Starija' is used as an adjective modifying 'generacija', indicating it is referring to an older age group of people.