Guilt regarding dubious social conventions (7)
I believe the answer is:
remorse
'guilt' is the definition.
(feeling guilty)
'regarding dubious social conventions' is the wordplay.
'regarding' becomes 're' ('re' means regarding or about).
'dubious social conventions' becomes 'morse' (I can't justify this - if you can you should believe this answer much more).
're'+'morse'='REMORSE'
Can you help me to learn more?
(Other definitions for remorse that I've seen before include "compassion" , "Sorrow for wrongs committed" , "Gnawing pain of conscience" , "Regret for wrong" , "Distress from a sense of guilt" .)