Small feature (6)
I believe the answer is:
detail
'small feature' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for detail that I've seen before include "Individual fact or feature, may be unimportant" , "An individual item or element" , "A piece of information, may be minor" , "Relate minutely" , "Small or important part" .)