This is the 556th most frequent Croatian word.
obje
"Obje" means "both" in English.
Here, 'obje' is used to refer to two feminine nouns (knjige - books) collectively.
Obje knjige su na stolu.
Both books are on the table.
In this sentence, 'obje' modifies the feminine plural noun 'prijateljice' (friends) to indicate both of them.
Vidjela sam obje prijateljice u gradu.
I saw both friends in the city.
In this example, 'obje' is used in the nominative case to refer to two feminine entities already mentioned, emphasizing their collective agreement.