The most common and most likely answer to this crossword clue is the 8 letter word ROTATION
I've seen this crossword clue in The Times
R
O
T
A
T
I
O
N
More clues leading to the result ROTATION
- Turn of old French actor performing after end of war
- Run over by French comedian riding cycle
- Turn helping to secure book collection
- Regular changing of crops to set up in allotment
- Revolution helping to protect religious books
- Turning to limit supply
- Turn to in helping cycle
- No one cheers over following rubbish turn
- Cycle race’s start ain’t too haphazard
- Technique for growing crops of sort regularly planted in allotment
Buddy explains!

The straight part
We know that "Turn" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case turn = rotation.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ROTATION mean?
ROTATION noun- The act of turning around a centre or an axis.
- A single complete cycle around a centre or an axis.
- A regular variation in a sequence, such as to even-out wear, or people taking turns in a task; a duty roster.
- An operation on a metric space that is a continuous isometry and fixes at least one point.
- The set of starting pitchers of a team.
- The step during takeoff when the pilot commands the vehicle to lift the nose wheel off the ground during the takeoff roll. (see also: V2)
- Repeated play on a radio station, etc.