periostracum

[ per-ee-os-truh-kuhm ]

noun,plural per·i·os·tra·ca [per-ee-os-truh-kuh]. /ˌpɛr iˈɒs trə kə/.
  1. the external, chitinlike covering of the shell of certain mollusks that protects the limy portion from acids.

Origin of periostracum

1
1830–40; <New Latin, equivalent to peri-peri- + ostracum a shell <Greek óstrakon.See oyster

Other words from periostracum

  • per·i·os·tra·cal, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024