Story, on reflection, is charged with joy (7)
I believe the answer is:
elation
'joy' is the definition.
(I know that elation is a type of joy)
'story on reflection is charged' is the wordplay.
'story' becomes 'tale' (synonyms).
'on reflection' shows that the letters should be reversed in order.
'is charged' becomes 'ion' (I've seen this in other clues).
'tale' in reverse letter order is 'elat'.
'elat'+'ion'='ELATION'
'with' acts as a link.
(Other definitions for elation that I've seen before include "Exaltation" , "There's great joy" , "Feeling of intense delight" , "Euphoria of toenail" , "Feeling of joy for it alone" .)