Belittle your and my attitude (9)
I believe the answer is:
demeanour
'attitude' is the definition.
(I know that demeanour is a type of attitude)
'belittle your and my' is the wordplay.
'belittle' becomes 'demean' (belittle can mean to demean or patronise).
'your and my' becomes 'our' (I've seen this in another clue).
'demean'+'our'='DEMEANOUR'
(Other definitions for demeanour that I've seen before include "Outward bearing" , "Enamoured of the way a person behaves" , "Appearance and attitude" , "Manner of behaving towards others" , "Look" .)