balance, wobble, rock, sway, totter, waver, tremble, stagger:
She screamed when she saw Bruce teetering on the edge of the precipice.
Advanced English Dictionary
+verb [V] to stand or move in an unsteady way so that you look as if you are going to fall: She teetered after him in her high-heeled shoes. Idioms: teeter on the brink / edge of sth to be very close to a very unpleasant or dangerous situation: The country is teetering on the brink of civil war.
Random quote: Mind is everything: muscle, pieces of rubber. All that I am, I am because of my mind.: Paavo Nurmi