Sharp turn by Oliver? (5)
I believe the answer is:
twist
'oliver?' is the definition.
(I've seen this before)
'sharp turn by' is the wordplay.
'sharp' becomes 'wist' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'turn' becomes 't' (abbreviation in Oxford Dictionary of Abbreviations).
'by' means one lot of letters go next to another.
'wist' after 't' is 'TWIST'.
Can you help me to learn more?
(Other definitions for twist that I've seen before include "Turn; cheat" , "Distort; apply torque" , "See Oliver" , "One who wanted more" , "See 14" .)