Balance precariously (6)
I believe the answer is:
teeter
'balance precariously' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for teeter that I've seen before include "Sway, as if about to fall" , "See-saw on the edge" , "Rock unsteadily on edge" , "Sway back and forth, on the brink perhaps" , "Stand or move unsteadily" .)