Unwakable state (4)
I believe the answer is:
coma
'unwakable state' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for coma that I've seen before include "State of deep (often prolonged) unconsciousness" , "Deep trance" , "State of unconsciousness caused by illness" , "Unconsciousness from which person cannot be aroused" , "Unconscious state" .)