Weakness arrivin'? (11)
I believe the answer is:
shortcoming
'weakness' is the definition.
(I've seen this before)
'arrivin'?' is the wordplay.
I cannot really understand how this works, but
'arrivin'?' could be 'comin' ('coming' pronounced like 'arriving' was; 'come' can be a synonym of 'arrive') and 'comin' is found in the answer.
This explanation may well be incorrect...
(Other definitions for shortcoming that I've seen before include "Fault, defect" , "drawback" , "Weakness" , "A failing" .)