Knotted loop (5)
I believe the answer is:
noose
'knotted loop' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for noose that I've seen before include "Loop at the end of a rope" , "marriage, for a laugh" , "Snare, restraint" , "Rope around the neck" , "Circular loop" .)