No longer with it perhaps, using broken sentences (9)
I believe the answer is:
senescent
'no longer with it perhaps' is the definition.
(senescent means growing old)
'broken sentences' is the wordplay.
'broken' indicates anagramming the letters.
'sentences' anagrammed gives 'SENESCENT'.
'using' acts as a link.
(Other definitions for senescent that I've seen before include "Showing age-related deterioration" , "characteristic of old age" , "Showing signs of age" , "Growing old" , "Ageing" .)