Blue feathers (4)

I believe the answer is:

down

This clue is a double definition.

'blue' is the first definition.
(both can mean sad)

'feathers' is the second definition.
(down can mean bird feathers)

(Other definitions for down that I've seen before include "drink at speed" , "Fluff - sorrowful" , "Not working (computer)" , "Consume (drink), sad" , "Pillow filler - dejected" .)

I've seen this clue in The Guardian, The Telegraph, The Times, The Sunday Times, The Daily Express and The Mirror.

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