Remains of bird missing part of foot (5)
I believe the answer is:
chaff
'remains' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
(Other definitions for chaff that I've seen before include "Shucks" , "Rubbish" , "Corn husks - worthless stuff" , "shells" , "Worthless material (from corn)" .)