Neglected child with a condition (4)
I believe the answer is:
waif
'neglected child' is the definition.
(I've seen this before)
'with a condition' is the wordplay.
'with' becomes 'w' (abbreviation).
'condition' becomes 'if' (I've seen this in other clues).
'w'+'a'+'if'='WAIF'
(Other definitions for waif that I've seen before include "Orphan" , "Be incongruous" , "neglected issue" , "An unowned or abandoned child" , "Gamin" .)