Some of whatever Balzac’s expressed in words (6)
I believe the answer is:
verbal
'expressed in words' is the definition.
(I've seen this before)
'some of whatever balzac's' is the wordplay.
'some of' indicates a hidden word.
'VERBAL' is hidden in the letters of 'whatever balzacs'.
(Other definitions for verbal that I've seen before include "Sound (the hour); find (oil)" , "Expressed in words" , "Relating to words" , "statement to police" , "not written down" .)