Failing or defect (11)
I believe the answer is:
shortcoming
I believe this clue is a double definition.
'failing' is the first definition.
(I have seen 'A failing ' mean 'shortcoming' so perhaps 'failing' could also mean 'shortcoming')
'defect' is the second definition.
(thesaurus)
(Other definitions for shortcoming that I've seen before include "A failing" , "Fault, defect" , "Weakness" , "drawback" .)