Eider (noun)

1. A type of sea duck that breeds in the Arctic and is known for its soft, warm down feathers, which are used in making high-quality quilts and pillows.
2. The down from this bird.

Origin:

From old norse æðr, from proto-germanic *aidaz.

Examples:

1. The eider is a type of sea duck known for its warm, soft down feathers.
2. The eiderdown from the Arctic bird was highly valued for its insulating properties.
3. The quilt was filled with eiderdown for added warmth during the cold winter nights.
4. The pillow was filled with eiderdown for comfort and luxury.
5. The parka was filled with eiderdown to provide insulation against the cold Arctic winds.