One of five leaders on the electoral roll (5)
I believe the answer is:
voter
'one' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'five leaders on the electoral roll' is the wordplay.
'five' becomes 'V' (Roman numeral).
'leaders' indicates taking the first letters.
The initial letters of 'on the electoral roll' is 'oter'.
'v'+'oter'='VOTER'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for voter that I've seen before include "One could use PR" , "Cross writer" , "One exercising the ballot" , "one making sign of the cross" , "Overt (anag)" .)