English Dictionary

powder down

noun

A special type of down that occurs in a few groups of apparently unrelated birds. In some species, the tips of the barbules on the feathers disintegrate, forming fine particles of keratin; in others, powder grains come from cells that surround the barbules of growing feathers.

The bird's feathers are coated with a fine powder down.

意味（1）

A special type of down that occurs in a few groups of apparently unrelated birds. In some species, the tips of the barbules on the feathers disintegrate, forming fine particles of keratin; in others, powder grains come from cells that surround the barbules of growing feathers.

All parrots have powder down.