No-man's-land? (6,4)
I believe the answer is:
animal farm
'no-man's-land?' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see a link between them that I can't see?
'man's-land?' is the wordplay.
'man's' becomes 'animal' (I can't justify this - if you can you should believe this answer much more).
'land?' becomes 'farm' (I have seen 'Agricultural land ' mean 'farm' so perhaps 'land' could also mean 'farm').
'animal'+'farm'='ANIMAL FARM'
(Other definitions for animal farm that I've seen before include "where Napoleon led" , "allegory" , "Book giving quote Four legs good, two legs bad" , "George Orwell novel" .)