periderm /perˈi-dûrm/

1. The horny cuticular covering of a hydroid colony
2. The cork cambium with the cork and other tissues derived from it, forming a protective outer covering in plants

• ortho
• ortho-
• orthoaxes
• orthoaxis
• orthoboracic acid
• orthoborate
• orthoborates
• orthocaine
• orthocaines
• orthocentre
• orthocentres
• Orthoceras
• orthochromatic
• orthoclase
• orthoclases
• ortho-compound
• ortho-compounds
• ortho-cousin
• ortho-cousins
• orthodiagonal
• orthodiagonals
• orthodontia
• orthodontias
• orthodontic
• orthodontically