Unresponsive state (4)
I believe the answer is:
coma
'unresponsive state' is the definition.
(a coma is an unconscious state)
This is the entire clue.
(Other definitions for coma that I've seen before include "Unconscious state" , "State of unconsciousness caused by illness" , "Unconsciousness from which person cannot be aroused" , "State of insensibility" , "Stupor" .)