One baring all (6)
I believe the answer is:
nudist
'one baring all' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for nudist that I've seen before include "exhibitionist" , "Dustin (anag)" , "one leading a bare existence" , "One going unclothed" , "Person who believes in going unclothed" .)