Not many working? It means the opposite (7)
I believe the answer is:
antonym
'it means the opposite' is the definition.
(I've seen this before)
'not many working?' is the wordplay.
'working?' indicates an anagram.
'not'+'many'='notmany'
'notmany' with letters rearranged gives 'ANTONYM'.
(Other definitions for antonym that I've seen before include "A word's opposite" , "Word that means the opposite of another" , "As 'happy' is to 'sad' or 'long' to 'short'" , "that means reverse" , "Opposite-meaning word" .)