Drowsy; sluggish (9)
I believe the answer is:
lethargic
This clue is a double definition.
'drowsy' is the first definition.
(thesaurus)
'sluggish' is the second definition.
(similar in meaning)
(Other definitions for lethargic that I've seen before include "low in vitality" , "Listless" , "Lacking in energy or vitality" , "Unenergetic" , "languid" .)