Soporific (8)
I believe the answer is:
comatose
'soporific' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for comatose that I've seen before include "Somnolent" , "In a drowsy or semi-conscious state" , "Insensible or unconscious" , "Come to as in drowsy condition" , "Fast asleep" .)