Recover from illnesses, so perhaps on the turn (9)
I believe the answer is:
repossess
'recover' is the definition.
(thesaurus)
'from illnesses so perhaps on the turn' is the wordplay.
'from' indicates a hidden word.
'on the turn' is a reversal indicator.
'ssessoper' can be found hidden inside 'illnesses so perhaps'.
'ssessoper' written backwards gives 'REPOSSESS'.
(Other definitions for repossess that I've seen before include "Take back (due to non-payment)" , "Seize assets" , "Take back (goods)" , "Retake ownership" , "Take back ownership" .)