Waxed European moustache, finally decorating face (8)
I believe the answer is:
polished
'waxed' is the definition.
Both the definition and answer are adjectives. Maybe there's an association between them I don't understand?
'european moustache finally decorating face' is the wordplay.
'european' becomes 'Polish ' (Poland is in Europe).
'finally' indicates one should take the final letters.
'decorating face' becomes 'd' (I can't explain this - if you can you should give a lot more credence to this answer).
The last letter of 'moustache' is 'e'.
'polish'+'e'+'d'='POLISHED'
Can you help me to learn more?
(Other definitions for polished that I've seen before include "Shiny; rubbed" , "Genteel - flawless" , "Shining or refined" , "Difference, statistical quantity" , "Buffed to a shine" .)