Rent out a book to candidate (7)
I believe the answer is:
entrant
'to candidate' is the definition.
(I've seen this before)
'rent out a book' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'book' becomes 'nt' (New Testament).
'rent' with letters rearranged gives 'entr'.
'entr'+'a'+'nt'='ENTRANT'
(Other definitions for entrant that I've seen before include "Newcomer" , "Someone signing up for a competition" , "New member or competitor" , "Competitor, contestant" , "New participant" .)