When established, something to one's credit (5)
I believe the answer is:
asset
'something to one's credit' is the definition.
I can't judge whether this definition defines the answer.
'when established' is the wordplay.
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'established' becomes 'set' (set can mean established or agreed upon).
'as'+'set'='ASSET'
Can you help me to learn more?
(Other definitions for asset that I've seen before include "one liable to be stripped?" , "Anything of value" , "Something valuable to have" , "A useful thing l" , "Boon" .)