Former wife with stories about one's feats (8)
I believe the answer is:
exploits
'feats' is the definition.
('exploit' can be a synonym of 'feat')
'former wife with stories about one's' is the wordplay.
'former wife' becomes 'ex'.
'with' means one lot of letters go next to another.
'stories' becomes 'plots' (plot is a kind of story**).
'about' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'plots' placed around 'i' is 'ploits'.
'ex'+'ploits'='EXPLOITS'
(Other definitions for exploits that I've seen before include "Takes advantage of - daring deeds?" , "Manipulates someone to one's own advantage" , "Unfairly uses" , "Bold or daring feats" .)