That woman’s nothing? Au contraire! (4)
I believe the answer is:
hero
'au contraire' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?
'that woman's nothing?' is the wordplay.
'that woman' becomes 'her' (her refers to a woman).
'nothing?' becomes 'O' (looks like zero - 0).
'her'+'o'='HERO'
Can you help me to learn more?
(Other definitions for hero that I've seen before include "girl a ring" , "Chief male character in story or film - probably very brave" , "Person distinguished by exceptional courage" , "Illustrious person" , "Male protagonist" .)