Crossword Genius

Release (a knot) (4)

Ross

I believe the answer is:

undo

(Other definitions for undo that I've seen before include "Take back" , "Release fastening" , "set free" , "(4)" , "Spoil" .)

I've seen this clue in The Sun.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.