periostracum /per-i-osˈtrə-kəm/

The horny outer layer of a mollusc's shell

• narrowcasting
• narrowcastings
• narrowcasts
• narrow circumstances
• narrowed
• narrower
• narrow escape
• narrow escapes
• narrowest
• narrow gauge
• narrow-gauge
• narrow gauges
• narrowing
• narrowings
• narrowly
• narrow-minded
• narrow-mindedly
• narrow-mindedness
• narrowness
• narrownesses
• narrows
• narrow seas
• narrow squeak
• narrow squeaks
• narthex