Half of us are this, perhaps? (6)
I believe the answer is:
sexist
'this perhaps?' is the definition.
The definition suggests a singular noun which matches the answer.
'half of us are' is the wordplay.
'half of' means to take half the letters.
'are' becomes 'exist' ('they are' means 'they exist').
'us' cut in half is 's'.
's'+'exist'='SEXIST'
Can you help me to learn more?
(Other definitions for sexist that I've seen before include "Offensive about a particular gender" , "discriminating against women?" , "that's nicer to fellows?" , "Bigot" , "Displaying gender discrimination" .)