Turning a little subdued, drinking a wine is what’s wanted (11)
I believe the answer is:
desideratum
'what's wanted' is the definition.
I can't judge whether this defines the answer.
'turning a little subdued drinking a wine is' is the wordplay.
'turning' says the letters should be written backwards.
'a little subdued' becomes 'muted' (muted can mean subdued or quiet).
'drinking' means one lot of letters goes inside another (inserted letters are consumed or drunk).
'wine' becomes 'red' (red is a type of wine).
'a'+'red'+'is'='aredis'
'muted' going around 'aredis' is 'mutaredised'.
'mutaredised' in reverse letter order is 'DESIDERATUM'.
(Other definitions for desideratum that I've seen before include "Something much wanted" , "Something much needed" , "Something needed or wanted" , "As requirement" , "Essential" .)