1. Region around the mouth in various invertebrates
   "The sea urchin's peristome contained numerous small teeth"
    
2. (botany) fringe of toothlike appendages surrounding the mouth of a moss capsule
   "The peristome helps regulate the release of spores from the moss capsule"

Derived forms: peristomes

Type of: anatomical structure, bodily structure, body structure, complex body part, enation, plant process, structure

Part of: capsule, invertebrate

Encyclopedia: Peristome