Pick exam on subject of poll (9)
I believe the answer is:
electoral
'subject of poll' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'pick exam on' is the wordplay.
'pick' becomes 'elect' (to elect is to pick or select).
'exam' becomes 'oral' (spoken academic test).
'on' is a charade indicator (letters next to each other).
'elect'+'oral'='ELECTORAL'
Can you help me to learn more?
(Other definitions for electoral that I've seen before include "kind of US college" , "Relating to the voting system" , "made up of voters" , "type of roll" , "Like popular choice" .)