Incisive English coming from satirical novelist (5)
I believe the answer is:
sharp
'incisive' is the definition.
('sharp' can be a synonym of 'incisive')
I cannot understand how the remainder of the clue works.
(Other definitions for sharp that I've seen before include "Keen-edged" , "Fly - biting" , "Clear-cut" , "Punctually; raised note" , "Clearly defined (image)" .)