integument

noun3

1. •
   A shell or other outer protective layer.

   • […] if we're moved by the book's condemnation of a world wounded by exploitation, where the drive for profit hobbles the mass of humanity, bolsters vast integuments of oppression and repression, […] — 2022
2. •
   An outer protective covering such as the feathers or skin of an animal, a rind or shell.

   • Sarsem became a naked young epicene in an integument of lavender scales with puffs of purple hair like pom-poms growing down his back. — 1984
3. •
   The outer layer of an ovule, which develops into the seed coat.

   • Her active living was suspended, but underneath, in the darkness, something was coming to pass. If only she could break through the last integuments! — 1920