Making sport of polishing things off (8)
I believe the answer is:
scoffing
'making sport' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scoffing that I've seen before include "eating" , "taking the mickey" , "Rapidly putting away" , "Consumption" .)