Wheat husk (4)
I believe the answer is:
bran
'wheat husk' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bran that I've seen before include "Type of edible fibre" , "Husks of cereal seeds sifted from flour" , "Coarse meal for horse food" , "Healthy breakfast" , "Pieces of grain husk after milling" .)