Unusually adroit about turn by a bookish examiner (7)
I believe the answer is:
auditor
'a bookish examiner' is the definition.
'auditor' can be an answer for 'examiner' (an auditor examines accounts etc). I am not sure about the 'a bookish' bit.
'unusually adroit about turn' is the wordplay.
'unusually' indicates an anagram.
'about' means one lot of letters goes inside another.
'turn' becomes 'U' (a 'U-turn' is a kind of turn).
'adroit' anagrammed gives 'aditor'.
'aditor' placed around 'u' is 'AUDITOR'.
'by' acts as a link.
Can you help me to learn more?
(Other definitions for auditor that I've seen before include "He'll check the accounts" , "One who checks accounts" , "Accounts verifier" , "Person who listens" , "Accountant - listener" .)