Muscle which turns either way (7)
I believe the answer is:
rotator
'muscle' is the definition.
(I've seen this in another clue)
'turns either way' is the wordplay.
I cannot quite understand how this works, but
'either' could be 'or' (I've seen this in another clue) and 'or' is found in the answer.
'way' could be 'r' (abbreviation for right) and 'r' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'which' is the link.
Can you help me to learn more?
(Other definitions for rotator that I've seen before include "Muscle that turns" , "Muscle that revolves a part of the body on its axis" , "this one is for turning" , "Something that turns" , "Something turning" .)