Lifeless? Exactly! (4)
I believe the answer is:
dead
This clue is a double definition.
'lifeless?' is the first definition.
('dead' can be a synonym of 'lifeless')
'exactly' is the second definition.
(thesaurus)
(Other definitions for dead that I've seen before include "Defunct" , "Late; exact" , "Lookalike" , "Gone to meet one's Maker" , "Not functioning; numb" .)