Wobble on the brink (6)
I believe the answer is:
teeter
'wobble on the brink' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for teeter that I've seen before include "Stand or move unsteadily" , "Seesaw, totter" , "Rock precariously on the edge" , "Totter, wobble" , "Rock unsteadily on feet" .)