Repeating appeal to buy historic period’s books (7)
I believe the answer is:
iterant
'repeating' is the definition.
(I've seen this before)
'appeal to buy historic period's books' is the wordplay.
I cannot really see how this works, but
'appeal' could be 'it' and 'it' is located in the answer.
'books' could be 'nt' (abbreviation for New Testament) and 'nt' is found in the answer.
'period' could be 'era' (era is a kind of period) and 'era' is found within the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for iterant that I've seen before include "Repeating" , "Echoing" .)