Spiritless detainee an Italian leader imprisoned (9)
I believe the answer is:
inanimate
'spiritless' is the definition.
(I've seen this before)
'detainee an italian leader imprisoned' is the wordplay.
'detainee' becomes 'inmate'.
'leader' suggests taking the first letters.
'imprisoned' indicates putting letters inside.
The initial letter of 'italian' is 'i'.
'an'+'i'='ani'
'inmate' enclosing 'ani' is 'INANIMATE'.
(Other definitions for inanimate that I've seen before include "Not living" , "wooden" , "Lacking life" , "Unlikely to move" , "Showing no feeling" .)