Hidden store of money, reportedly (5)
I believe the answer is:
cache
'hidden store' is the definition.
(I've seen this in another clue)
'money reportedly' is the wordplay.
'money' becomes 'cash' (cash is a type of money).
'reportedly' shows a homophone (sound like).
'cash' sounds like 'CACHE'.
'of' acts as a link.
(Other definitions for cache that I've seen before include "Put away" , "Nest egg" , "Secret store, hoard" , "Hiding-place for treasure etc" , "memory" .)