Proust's novel state of shock (6)
I believe the answer is:
stupor
'state of shock' is the definition.
(I've seen this before)
'proust's novel' is the wordplay.
'novel' indicates anagramming the letters (letters in a new or novel order).
'proust' with letters rearranged gives 'STUPOR'.
(Other definitions for stupor that I've seen before include "Semi-comatose state" , "Coma - lassitude" , "state of somnolence" , "Marginal consciousness" , "State of insensibility or near-unconsciousness" .)