Grand party given by police in church ground (9)
I believe the answer is:
graveyard
'church ground' is the definition.
(I've seen this before)
'grand party given by police in' is the wordplay.
'grand' becomes 'g' (G is short for ground as in a thousand).
'party' becomes 'rave' (type of dance party).
'given by' is a charade indicator (letters next to each other).
'police in' becomes 'yard' (I've seen this before. I am not sure about the 'in' bit.).
'g'+'rave'+'yard'='GRAVEYARD'
Can you help me to learn more?
(Other definitions for graveyard that I've seen before include "church ground" , "Burial ground" , "Final destination" , "Cemetery" , "remains here" .)