Going round in frayed underwear — or without any clothes at all (4)
I believe the answer is:
'without any clothes at all' is the definition.
I can't judge whether this definition defines the answer.
'going round in frayed underwear' is the wordplay.
'going round' says the letters should be written backwards.
'in' says the answer is hidden in the clue.
'edun' is hidden in the letters of 'frayed underwear'.
'edun' back-to-front is 'NUDE'.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for nude that I've seen before include "Wearing no clothes" , "The Thinker, maybe" , "Wearing one's birthday suit" , "Naked person" , "not in gear" .)