Removes, as a knot (6)
I believe the answer is:
unties
'removes as a knot' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for unties that I've seen before include "Opens knot to release" , "Undoes, loosens a knot" , "Undoes, a knot perhaps" , "Loosens laces" .)