China's in marginally overlapping dioceses, it appears (9)
I believe the answer is:
seemingly
'it appears' is the definition.
('it appears' can mean apparently or seemingly)
'china's in marginally overlapping dioceses' is the wordplay.
'china' becomes 'ming' (Chinese porcelain from the Ming dynasty).
'in' indicates putting letters inside.
'marginally overlapping dioceses' becomes 'seely' (I can't explain this - if you can you should give a lot more credence to this answer).
'ming' placed inside 'seely' is 'SEEMINGLY'.
(Other definitions for seemingly that I've seen before include "Apparently" , "So it would appear" .)