1. The externally visible cartilaginous structure of the external ear
   "The cat's pinna twitched at the sound";
   - auricle, ear
    
2. Division of a usually pinnately divided leaf
   "The fern's frond was composed of many delicate pinnae";
   - pinnule

Derived forms: pinnae

Type of: cartilaginous structure, leaflet

Part of: external ear, outer ear

Encyclopedia: Pinna, Paul