Man in the street polite to leaders? I'm afraid not! (8)
I believe the answer is:
civilian
'man in the street' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'polite to leaders? i'm afraid not' is the wordplay.
'polite' becomes 'civil' ('civil' can be a synonym of 'polite').
'to leaders?' indicates taking the first letters (I've seen 'leader' mean this).
The initial letters of 'im afraid not' is 'ian'.
'civil'+'ian'='CIVILIAN'
Can you help me to learn more?
(Other definitions for civilian that I've seen before include "Non-combatant" , "Member of a country" , "Forces apart any person" , "Nonmilitary person" , "He's not in the clergy or military" .)