Forelimb feature (4)
I believe the answer is:
ulna
'forelimb feature' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ulna that I've seen before include "Inner bone of the human forearm" , "Radius partner" , "Part of bone-structure" , "part of arm" , "Uneven" .)