Unable to do things for oneself (8)
I believe the answer is:
helpless
'unable to do things for oneself' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for helpless that I've seen before include "Unable to do things for oneself" , "Impotent" , "Unaided" , "Powerless or incapacitated" , "Unable to defend oneself" .)