Wheel surround revolving in every turn (4)
I believe the answer is:
tyre
'wheel surround' is the definition.
(a tyre covers a wheel)
'revolving in every turn' is the wordplay.
'revolving' says the letters should be written in reverse.
'in' indicates a hidden word.
'eryt' is hidden in the letters of 'every turn'.
'eryt' backwards is 'TYRE'.
(Other definitions for tyre that I've seen before include "A spare one around the tummy is fat" , "Wheel cover; port" , "Rubber wheel cover" , "Wheel-hoop" , "Rubber ring on a wheel" .)