This is the 705th most frequent Slovenian word.
zadnja
"Zadnja" in English means "last" or "rear," depending on the context.
In this sentence, 'zadnja' is used as an adjective meaning 'back' to describe the location of the doors.
Zadnja vrata so vedno zaklenjena.
The back door is always locked.
Here, 'zadnja' modifies 'oddaja' to mean 'last', referring to the final episode in order.
To je bila zadnja oddaja te sezone.
This was the last episode of this season.
In this case, 'zadnja' is used as an adjective to mean 'last', indicating the position associated with the end of ranking.