Waves mug, sharing fine veneer (7)
I believe the answer is:
surface
'veneer' is the definition.
(thesaurus)
'waves mug sharing fine' is the wordplay.
I cannot really understand how this works, but
'waves' could be 'surf' (surf can mean foam from waves) and 'surf' is present in the answer.
'fine' could be 'ace' (I've seen this in other clues) and 'ace' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for surface that I've seen before include "Outside; rise to the top" , "Come up for air" , "skin" , "Outside layer" , "Become apparent" .)