It revolves either way (5)
I believe the answer is:
rotor
I believe this is a double definition.
'it revolves' is the first definition.
(I've seen this before)
'either way' is the second definition.
(Other definitions for rotor that I've seen before include "Revolving component" , "one lifting chopper?" , "Reversible piece of moving machinery?" , "Turning motor part" , "Part of electric motor" .)