Degrade your, and my, carriage (9)
I believe the answer is:
demeanour
'carriage' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'degrade your and my' is the wordplay.
'degrade' becomes 'demean' (synonyms).
'your and my' becomes 'our' (I've seen this in another clue).
'demean'+'our'='DEMEANOUR'
Can you help me to learn more?
(Other definitions for demeanour that I've seen before include "Outward bearing" , "Conduct" , "Appearance and attitude" , "Enamoured of the way a person behaves" , "Manner of behaving towards others" .)