eiderdown

1. (uncountable) The down of the eider duck, used for stuffing pillows and quilts.Examples: "A great sea lifted us high and, crashing down with a deafening roar, carried us swiftly along on light foam as soft as eiderdown."uncountable

2. (countable) A quilt stuffed with this down.Examples: "The landlord was near spraining his wrist, and I told him for heaven’s sake to quit—the bed was soft enough to suit me, and I did not know how all the planing in the world could make eider down of a pine plank."; "I entered. It was a very small room, overcrowded with furniture of the style which the French know as Louis Philippe. There was a large wooden bedstead on which was a billowing red eiderdown, and there was a large wardrobe, a round table, a very small washstand, and two stuffed chairs covered with red rep."; "She jerked up in bed, clutching the eiderdown; her heart beat. What could it be?"countable