Swallow displaying soft feathers (4)
I believe the answer is:
down
I believe this is a double definition.
'swallow' is the first definition.
(thesaurus)
'soft feathers' is the second definition.
(I've seen this before)
'displaying' acts as a link.
(Other definitions for down that I've seen before include "See 3" , "Immediately" , "Where this clue is going" , "Not working (computer)" , "Depressed; swallow" .)