Inefficient or helpless person (4,4)
I believe the answer is:
lame duck
'inefficient or helpless person' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lame duck that I've seen before include "Person in need of help, like footsore mallard" , "Person in need of help - like injured eider?" , "Someone no longer able to perform effectively" , "bankrupt" , "Ineffectual type" .)