manubrium [mǝ`nü·brē·ǝm] ANATOMY 1. The triangular cephalic portion of the sternum in humans and certain other mammals. 2. The median anterior portion of the sternum in birds. 3. The process of the malleus. BOTANY A cylindrical cell that projects inward from the middle of each shield composing the antheridium in stoneworts. INVERTEBRATE ZOOLOGY The elevation bearing the mouth in hydrozoan polyps. |