The most common and most likely answer to this crossword clue is the 7 letter word REREDOS
I've seen this crossword clue in The Guardian
R
E
R
E
D
O
S
More clues leading to the result REREDOS
- Notes saint in screen in church
- Limits of range and colour on very big screen
- Respecting cardinal, very large screen
- Screen some episode reruns backwards
- Taking time, restored tattered screen
- Red rose embroidered for church screen
- More resentful about journalist splitting screen
- Screen some episode re-runs making a comeback
- Screen in episode rerun backwards
- Screen showing fresh e-orders
Buddy explains!

The straight part
We know that "church screen" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case church screen = reredos.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does REREDOS mean?
REREDOS noun- (chiefly Western Christianity) A screen or decoration behind the altar in a church, usually depicting religious iconography or images, akin to the iconostasis of the Eastern Churches.
- The back of an open fire-hearth, in medieval halls.