Voter part reversed about spinning etc. (7)
I believe the answer is:
elector
'voter' is the definition.
('elector' can be a synonym of 'voter')
'part reversed about spinning etc' is the wordplay.
'part' becomes 'role' ('role' can be a synonym of 'part'**).
'reversed' says the letters should be written in reverse.
'about' indicates putting letters inside.
'spinning' is an anagram indicator.
'role' reversed gives 'elor'.
'etc' anagrammed gives 'ect'.
'elor' going around 'ect' is 'ELECTOR'.
(Other definitions for elector that I've seen before include "One with the power to cross" , "might he make one cross?" , "One may make one cross" , "A prince of the Holy Roman Empire" , "I choose" .)