Swallow fluffy feathers (4)
I believe the answer is:
down
I believe this clue is a double definition.
'swallow' is the first definition.
(I know that down is a more specific form of eat up)
'fluffy feathers' is the second definition.
(I've seen this in another clue)
(Other definitions for down that I've seen before include "Depressed; swallow" , "See 1" , "Some 13 Acrosses" , "Melancholy" , "See 18" .)