After whisky having a go at carol singing (10)
I believe the answer is:
wassailing
'singing' is the definition.
(wassailing is a kind of singing)
'after whisky having a go at carol' is the wordplay.
'after' is a charade indicator (letters next to each other).
'whisky' becomes 'W' (phonetic alphabet: alpha, bravo, charlie etc.).
'having' means one lot of letters go next to another.
'a go at' becomes 'assail' (I've seen this in another clue).
'carol' becomes 'ing' (I can't justify this - if you can you should give a lot more credence to this answer).
'w'+'assail'='wassail'
'wassail' next to 'ing' is 'WASSAILING'.
Can you help me to learn more?
(Other definitions for wassailing that I've seen before include "carousing" , "making merry" , "merrymaking" , "revelry" .)