Art of speaking (8)
I believe the answer is:
rhetoric
'art of speaking' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rhetoric that I've seen before include "Language used for impressive or exaggerated sound" , "The art of oratory" , "Impressive language in public speaking" , "High-flown speech" , "insincere stuff" .)