Like a twisted cord that's not very good (4)
I believe the answer is:
ropy
I believe this clue is a double definition.
'like a twisted cord' is the first definition.
'not very good' is the second definition.
(I've seen this before)
'that's' is the link.
(Other definitions for ropy that I've seen before include "Slightly unwell" , "Of dubious quality" , "Slightly off-colour" , "Of poor quality (informal)" , "Not very good" .)