noun (plural umbones or umbos)
- (Armor) The boss of a shield, at or near the middle, and usually projecting, sometimes in a sharp spike.
- 1786: It is thirteen inches diameter, made of wood covered with leather, and an iron plate decorated with nails and mouldings; the boss or umbo projects four inches. — Francis Grose, A Treatise on Ancient Armour and Weapons, page xii.
- A boss, or rounded elevation, or a corresponding depression, in a palate, disk, or membrane; as, the umbo in the integument of the larví¦ of echinoderms or in the tympanic membrane of the ear.
- (zoology) One of the lateral prominence just above the hinge of a bivalve shell.
- A mythical beast traditionally represented as having the legs of a buck, the body of a horse, the tail of a lion with a single spiral horn on its head; a symbol of virginity.
- A heraldic representation of such a beast used as a charge or as a supporter; as in the arms of Great Britain and of Scotland.
- A mistranslation by the King James Bible (wild ox according to RSV). Young Earth Creationists and Fundamentalists believe the Unicorn to be some type of extinct one horned animal, possibly a dinosaur:
- Will the be willing to serve thee, or abide by thy crib? Canst thou bind the with his band in the furrow? Or will he harrow the valleys after thee? " Job 39:9-10 KJV.