A chapter includes stories (8)
I believe the answer is:
accounts
'stories' is the definition.
('account' can be a synonym of 'story')
'a chapter includes' is the wordplay.
'chapter' becomes 'c'.
'includes' becomes 'counts' (counting is a kind of including).
'a'+'c'+'counts'='ACCOUNTS'
(Other definitions for accounts that I've seen before include "Gives financial reckoning, or explains cause" , "Narrative descriptions of events" , "Statements of financial transactions" , "Reports of events" , "Records of financial transactions (8)" .)