<p><strong>Noun</strong></p><ul><li>A boss on a shield, as one at the center of a circular shield.</li><li>Any similar boss or protuberance.</li><li>Zoology: The beak of a bivalve shell; the protuberance of each valve above the hinge.</li><li>Anatomy: The depressed area on the outer surface of the tympanic membrane.</li><li>A blunt or rounded protuberance arising from a surface, as on a pine cone scale.</li></ul>