District hospital located below a Hilton (6)
I believe the answer is:
parish
'district' is the definition.
(parish is a kind of district)
'hospital located below a hilton' is the wordplay.
'hospital' becomes 'H' (abbreviation for hospital).
'located below' means one lot of letters go next to another.
'a hilton' becomes 'paris' (I can't explain this - if you can you should give a lot more credence to this answer).
'h' after 'paris' is 'PARISH'.
Can you help me to learn more?
(Other definitions for parish that I've seen before include "In Louisiana a county" , "District within county" , "Unit of local government" , "administrative district" , "Administrative area within a diocese" .)