Knotty problem unravelling ropes (5)

I believe the answer is:

poser

'knotty problem' is the definition.
(I've seen this in another clue)

'unravelling ropes' is the wordplay.
'unravelling' is an anagram indicator.
'ropes' is an anagram of 'POSER'.

(Other definitions for poser that I've seen before include "Toughie" , "Puzzling question for the model" , "Particularly baffling problem" , "Tricky problem" , "Exhibitionist" .)

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app