Every other (9)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
alternate
'every other' is the definition.
(synonyms)
This is all the clue.
(Other definitions for alternate that I've seen before include "Change from one thing to another by turns" , "Happening or following in turns, one after the other" , "Act reciprocally" , "Happen in turns, rotate" , "Occur in turn repeatedly" .)