### Clue: Overweening republican seen in old marketplace returning books (8)
### Answer: ARROGANT 
 ### Explanation: Definition: Overweening
 R(abbrev. for a member of the Republican Party, especially in the USA) **contained in**(seen in) **reversal of**(returning) AGORA(a marketplace in ancient Greece) + NT(abbrev. for the New Testament, the collection of books in the Christian Bible).