Churlish scoundrel with bad name say returning alone (12)

'churlish' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?

'scoundrel with bad name say returning alone' is the wordplay.
'scoundrel with' becomes 'cur' (I can't explain this - if you can you should believe this answer much more).
'bad name' becomes 'mud' (if someone's 'name is mud' they are a disgrace).
'say' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'returning' says the letters should be written in reverse.
'alone' becomes 'only' (synonyms).
'eg' back-to-front is 'ge'.
'cur'+'mud'+'ge'+'only'='CURMUDGEONLY'

Can you help me to learn more?