It's occupied in religious worship (3)
I believe the answer is:
pew
'worship' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for pew that I've seen before include "Long church seat" , "Bench-like seat in a church" , "Part of flock sitting here" , "Where some of the flock rest" , "Long bench in a church" .)