Robin Cook bestseller (4)
I believe the answer is:
coma
'robin cook bestseller' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for coma that I've seen before include "State of unconsciousness caused by illness" , "Stupor" , "long sleep" , "Unconsciousness from which person cannot be aroused" , "Deep trance" .)