Walked nervously back and forth
I believe the answer is:
paced
'walked nervously back and forth' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for paced that I've seen before include "Steadily walked" , "assist an athlete" , "Measured (a distance) by walking" , "Walked at a steady speed" , "Measured (a distance) in steps" .)