This is the 15540th most frequent Russian word.
престарелого
Aged; elderly.
The word 'престарелого' is used in the genitive case to describe the ownership or characteristic pertaining to the home, specifically referring to elderly individuals.
Посетили дом престарелого в нашем городе.
We visited the retirement home in our city.
Here, 'престарелого' is in the genitive case to link it with 'поколения' (generation), indicating the characteristic of being elderly.
Уважительно относитесь к престарелого поколения.
Treat the elderly generation with respect.
In this sentence, 'престарелого' modifies 'соседа' (neighbor) and is used in the accusative case as the direct object of the action.