Carol drinking wine that's awful (8)
I believe the answer is:
shocking
'awful' is the definition.
(thesaurus)
'carol drinking wine' is the wordplay.
'carol' becomes 'sing' (I've seen this in other clues).
'drinking' is an insertion indicator.
'wine' becomes 'hock' (hock is a kind of wine**).
'sing' placed around 'hock' is 'SHOCKING'.
'that's' is the link.
(Other definitions for shocking that I've seen before include "Traumatic" , "Horrific (pink?)" , "offering a jar" , "Appalling, causing disgust" , "Outrageous" .)