On the fence (7)
I believe the answer is:
neutral
'on the fence' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for neutral that I've seen before include "Not siding with any parties to a dispute" , "Impartial; colour" , "Not partisan, unbiased" , "Impartial, non-aligned" , "Not siding with any party" .)