Dark tassels twisted around first of ropes (8)
I believe the answer is:
starless
'dark' is the definition.
(I've seen this before)
'tassels twisted around first of ropes' is the wordplay.
'twisted' is an anagram indicator.
'around' indicates putting letters inside.
'first of ropes' becomes 'r' (1st letter of 'ropes').
'tassels' with letters rearranged gives 'staless'.
'staless' placed around 'r' is 'STARLESS'.
(Other definitions for starless that I've seen before include "with nobody famous appearing" , "Dark" , "Black" , "like a low-budget movie?" , "Like The Sky At Night, sometimes" .)