Unresponsive? Absolutely (4)
I believe the answer is:
dead
This clue is a double definition.
'unresponsive?' is the first definition.
(thesaurus)
'absolutely' is the second definition.
('dead' can be a synonym of 'absolutely')
(Other definitions for dead that I've seen before include "Not quick" , "Insensitive" , "Devoid of life" , "Lookalike" , "Not functioning; numb" .)