Screen has red centre and unusual rose edging (7)
I believe the answer is:
reredos
'unusual rose edging' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'screen has red centre and' is the wordplay.
'screen' becomes 'res' (I am not sure about this - if you are sure you should believe this answer much more).
'has' indicates putting letters inside.
'centre' means to look at the middle letters.
'and' becomes 'too'.
The centre of 'too' is 'o'.
'red'+'o'='redo'
'res' placed around 'redo' is 'REREDOS'.
Can you help me to learn more?
(Other definitions for reredos that I've seen before include "Ornamental screen behind a church altar" , "Church feature" , "Fireback" , "Back of fireplace" , "Red rose could show a screen behind the altar" .)