Auditor's dressed Natalie Wood (6)
I believe the answer is:
spruce
'wood' is the definition.
(I know that spruce is a type of wood)
I can't explain the remainder of the clue.
(Other definitions for spruce that I've seen before include "Well-groomed - tree" , "Smart, trim" , "Neat and trim like fir tree" , "thing for fairy to be on top of?" , "Neat - evergreen" .)