Rugged nun excited about original sinner (6)
I believe the answer is:
uneven
'rugged' is the definition.
(I've seen this before)
'nun excited about original sinner' is the wordplay.
'excited' indicates anagramming the letters.
'about' indicates putting letters inside.
'original sinner' becomes 'eve' (I've seen this in another clue).
'nun' with letters rearranged gives 'unn'.
'unn' enclosing 'eve' is 'UNEVEN'.
(Other definitions for uneven that I've seen before include "Not flat or level" , "Rough on the surface" , "Bumpy - odd" , "Irregular or not smooth" , "Rough, jagged" .)