Possible Clues:

• Duck with very soft feathers
• Spread down?
• Deer roaming round One Down's source
• Cover drops down for a duck
• Down for a pillow, sometimes
• From this one gets down to keep the temperature up
• Cardinal that's up and down, for example
• Down here, Princess said
• The turn of the colour, that is to say, may get down over one
• Get down from here?