1. A rounded or raised central part of a structure, such as the boss of a shield or the point of a mushroom cap
   "The umbo of the shield was decorated with intricate carvings"
    
2. A slight rounded elevation where the malleus attaches to the eardrum
   "The umbo is visible during otoscopic examination"
    
3. (zoology) the beak or protuberance near the hinge of a bivalve shell
   "The umbo is a distinctive feature on clam shells"

Derived forms: umbones, umbos

Type of: convex shape, convexity

Part of: eardrum, myringa, tympanic membrane, tympanum

Encyclopedia: Umbo