Unresolved issue, such as 1? (4,4)
I believe the answer is:
grey area
'as 1?' is the definition.
The definition suggests a singular noun which matches the answer.
'unresolved issue' is the wordplay.
'unresolved' becomes 'grey' (I can't justify this - if you can you should believe this answer much more).
'issue' becomes 'area' (area is a kind of issue).
'grey'+'area'='GREY AREA'
'such' acts as a link.
Can you help me to learn more?
(Other definitions for grey area that I've seen before include "Situation not clear-cut" , "retirement home?" , "Unclear situation" , "Ill-defined situation" , "something hard to define" .)