This is the 4212th most frequent Polish word.
dawnej
"Of former" or "of old."
The word 'dawnej' in this sentence functions as an adjective in the genitive case, agreeing with 'świetności' (glory). It means 'former' or 'previous.'
Pamiętam czasy dawnej świetności tego miejsca.
I remember the times of this place's former glory.
Here, 'dawnych' (plural) describes 'latach' ('years') in the locative case, emphasizing a time that is long past.
W dawnych latach wszystko wyglądało inaczej.
In former years, everything looked different.
In this sentence, 'dawnej' modifies 'epoki' ('era') in the genitive case, specifying the era's past characteristics.