Church screening blood through new rose window (7)
I believe the answer is:
reredos
'church screening blood' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'through new rose window' is the wordplay.
'through' means one lot of letters goes inside another (some letters go through others).
'new' indicates an anagram.
'window' becomes 'red' (I am not sure about this - if you are sure you should believe this answer much more).
'rose' is an anagram of 'reos'.
'reos' enclosing 'red' is 'REREDOS'.
Can you help me to learn more?
(Other definitions for reredos that I've seen before include "Back of fireplace" , "Ornamental screen behind a church altar" , "Wall decoration behind altar" , "Red rose could show a screen behind the altar" , "Hanging in church" .)