Ogre entering disreputable bar? Split! (7)
I believe the answer is:
divorce
'split' is the definition.
(divorcing is a kind of splitting)
'ogre entering disreputable bar?' is the wordplay.
'ogre' becomes 'orc'.
'entering' indicates putting letters inside.
'disreputable bar?' becomes 'dive'.
'orc' put into 'dive' is 'DIVORCE'.
(Other definitions for divorce that I've seen before include "Legal end to a marriage" , "Break-up" , "End one's marriage" , "Permanent separation" , "Get separated" .)