Fence-sitter's position (7)
I believe the answer is:
astride
'fence-sitter's position' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for astride that I've seen before include "Straddling (horse)" , "With legs stretched apart - tirades (anag)" , "With feet apart" , "With one leg on either side, as sitting on horse" , "Not side saddle" .)