Turning off oration? About time! (8)
I believe the answer is:
rotation
'turning' is the definition.
(I've seen this before)
'off oration? about time' is the wordplay.
'off' indicates anagramming the letters.
'about' means one lot of letters goes inside another.
'time' becomes 't'.
'oration' with letters rearranged gives 'rotaion'.
'rotaion' placed around 't' is 'ROTATION'.
(Other definitions for rotation that I've seen before include "Recurring sequence" , "altering of crops" , "Turn of a wheel" , "Process of turning" , "Out of control" .)