One who votes for the ultimate reader (7)
I believe the answer is:
elector
'one who votes' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'the ultimate reader' is the wordplay.
'ultimate' says to take the final letters.
'reader' becomes 'lector' ('lector' can be a synonym of 'reader').
The last letter of 'the' is 'e'.
'e'+'lector'='ELECTOR'
'for' is the link.
Can you help me to learn more?
(Other definitions for elector that I've seen before include "One exercising suffrage" , "Citizen with a right to vote" , "Crosses" , "A prince of the Holy Roman Empire" , "One whom may vote" .)