Curtain attachment (6)
I believe the answer is:
'curtain attachment' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tassel that I've seen before include "Grapefruit and tangerine hybrid" , "Decorative ending to a cord" , "Slates attached to ornamental bunch of threads" , "Part of maize plant" , "Bunch of cords fastened at one end" .)