Kingdoms concerned with charity (6)
I believe the answer is:
realms
'kingdoms' is the definition.
(I've seen this before)
'concerned with charity' is the wordplay.
'concerned with' becomes 're'.
'charity' becomes 'alms' (alms is a kind of charity).
're'+'alms'='REALMS'
(Other definitions for realms that I've seen before include "areas of interest" , "Kingdoms, or fields of interest" , "regions" , "Kingdoms, domains" , "Fields of activity or interest - sound monarchical" .)