Odd nun eventually getting cut down to size (6)
I believe the answer is:
uneven
'odd' is the definition.
(odd rather than even)
'nun eventually getting cut down to size' is the wordplay.
'getting cut down to size' indicates a hidden word.
'UNEVEN' is hidden within 'nun eventually'.
(Other definitions for uneven that I've seen before include "Inconsistant in quality" , "Rough, jagged" , "Inconsistent in quality or shape" , "That's odd" , "Not uniform or smooth" .)