Turnover now, finally one separated the chaff (8)
I believe the answer is:
winnowed
'turnover now finally one separated the chaff' is the definition.
I can't judge whether this defines the answer.
'turnover now finally one separated' is the wordplay.
'turnover' becomes 'win' (I can't justify this - if you can you should believe this answer much more).
'finally' suggests the final letters.
The final letters of 'one separated' are 'ed'.
'win'+'now'+'ed'='WINNOWED'
Can you help me to learn more?
(Other definitions for winnowed that I've seen before include "Removed (chaff) from grain" , "Used fan to remove chaff from grain" , "Separated the wheat from the chaff" .)