Walk as if about to fall (7)
I believe the answer is:
stagger
'walk as if about to fall' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for stagger that I've seen before include "Lurch; astound" , "Teeter" , "Walk unsteadily, from weakness or drink" , "Reel, walk unsteadily" , "bowl over" .)