One with accumulated funds in southern state (5)
I believe the answer is:
saver
'one with accumulated funds' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'southern state' is the wordplay.
'southern' becomes 's' (abbreviation).
'state' becomes 'aver' (both can mean to declare).
's'+'aver'='SAVER'
'in' is the link.
Can you help me to learn more?
(Other definitions for saver that I've seen before include "Person with spare cash?" , "One no doubt taking interest" , "Raves (anag.)" , "one in recovery" , "One budgeting" .)