Witty conversation or banter (8)
I believe the answer is:
repartee
I believe this clue is a double definition.
'witty conversation' is the first definition.
(I've seen this before)
'banter' is the second definition.
(both can mean jocular conversation)
(Other definitions for repartee that I've seen before include "Comic dialogue" , "Series of clever replies" , "Ready and witty retort" , "Lively exchange" , "Witty comments" .)