Moral excellence can be found in GOSH (8)
I believe the answer is:
goodness
'moral excellence' is the definition.
(being morally good)
'be found in gosh' is the wordplay.
I cannot quite see how this works, but
'be' could be 'go' (going is a kind of being) and 'go' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'can' is the link.
Can you help me to learn more?
(Other definitions for goodness that I've seen before include "Morality, generosity, kindness" , "Moral excellence" , "Virtue; excellence" , "Boy" , "Quality of being morally good or virtuous" .)