From Longman Dictionary of Contemporary Englisheiderdownei‧der‧down /ˈaɪdədaʊn $ -dər-/ noun [countable] DHHa thick warm cover for a bed, filled with duck feathers → duvet
Examples from the Corpus
eiderdown• Dot was in a wide high bed with white sheets, two pillows, two blankets and an eiderdown.• Sleep covered me like an eiderdown which some invisible nurse had picked up from the floor and put back on the bed.• Or him who said he heard the horn, moaning softly like an alarm clock under an eiderdown?• We had some hot weather, but with an eiderdown of cloud under the sun.• For night travelling, brass bedsteads with handsome eiderdown quilts were provided.• And yet his wool suit scrapes through the layer of eiderdown.• She stumbled to her feet, clutching the eiderdown around her, and opened her mouth to call to them.• Carefully she drew it out through the folds of the eiderdown and held it close to the flame of the nightlight.Origin eiderdown (1700-1800) Icelandic æthur type of duck + → DOWN2 