正せい羽う

noun

contour feather

Technical ornithological term for the typical body feathers that give a bird its shape and color, as opposed to down feathers or flight feathers.

• 正せい羽うは鳥とりの体たい表ひょう面めんを覆おおい、流りゅう線せん形けいの輪りん郭かくを作つくる。

  Contour feathers cover the bird's body surface and create a streamlined outline.