Mindless, stupid (9)
I believe the answer is:
senseless
I believe this clue is a double definition.
'mindless' is the first definition.
(I know that mindless can be written as senseless)
'stupid' is the second definition.
(similar in meaning)
(Other definitions for senseless that I've seen before include "Foolish; unconscious" , "Silly" , "Not marked by the use of reason" , "Mindless, pointless" , "Futile" .)