Decorative tuft of threads (6)
I believe the answer is:
tassel
'decorative tuft of threads' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tassel that I've seen before include "Bunch of cords as adornment" , "Hanging tuft of threads" , "Mortar board attachment" , "Bunch of cords fastened at one end" , "Hanging bunch of cords" .)