Granny or hitch (4)
I believe the answer is:
knot
'granny or hitch' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for knot that I've seen before include "Fastener - bird - unit of speed at sea" , "Tie, hitch" , "Fastening such as reef or granny" , "Tie; a cluster" , "Unit of length used in navigation" .)