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

• overactivity
• overacts
• over again
• over against
• over age
• over-age
• overage
• overages
• over-all
• overall
• overalled
• overalls
• overambitious
• over and above
• over and out
• over and over
• over and over again
• over-and-under
• over-anxiety
• over-anxious
• over-anxiously
• overarch
• overarched
• overarches
• overarching