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 Times, The Telegraph, The Mirror, The Daily Express, The Sunday Times and The Guardian.

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