This is the 13105th most frequent German word.
alternde
"Alternde" means "aging" (referring to something or someone growing older).
Here, 'alternde' is used as an attributive adjective modifying the noun 'Bevölkerung' (population), describing its ongoing process of aging.
Die alternde Bevölkerung stellt neue Herausforderungen für die Gesellschaft dar.
The aging population presents new challenges for society.
'Alternde' is applied as an attributive adjective describing 'Gebäude' (buildings), implying that these structures are in a state of aging.
Einige alternde Gebäude in der Altstadt sollen restauriert werden.
Some aging buildings in the old town are to be restored.
In this sentence, 'alternde' functions as an attributive adjective to 'Auto' (car), emphasizing the car's state of becoming older.