Merriam-Webster Collegiate Dictionary - horn

 or North Cape  geographical name cape NW Iceland HORN  noun  Etymology: Middle English, from Old English; akin to Old High German ~, Latin cornu, Greek keras  Date: before 12th century  1.  a. one of the usually paired bony processes that arise from the head of many ungulates and that are found in some extinct mammals and reptiles: as  (1) one of the permanent paired hollow sheaths of keratin usually present in both sexes of cattle and their relatives that function chiefly for defense and arise from a bony core anchored to the skull — see cow illustration  (2) antler  (3) a permanent solid ~ of keratin that is attached to the nasal bone of a rhinoceros  (4) one of a pair of permanent bone protuberances from the skull of a giraffe or okapi that are covered with hairy skin  b. a part like an animal's ~ attributed especially to the devil  c. a natural projection or excrescence from an animal resembling or suggestive of a ~  d.  (1) the tough fibrous material consisting chiefly of keratin that covers or forms the ~s of cattle and related animals, hooves, or other ~y parts (as claws or nails)  (2) a manufactured product (as a plastic) resembling ~  e. a hollow ~ used to hold something  2. something resembling or suggestive of a ~: as  a. one of the curved ends of a crescent  b. a sharp mountain peak  c. a body of land or water shaped like a ~  d. a beak-shaped part of an anvil  e. a high pommel of a saddle  f. cornu  3.  a. an animal's ~ used as a wind instrument  b. a brass wind instrument: as  (1) hunting ~  (2) French ~  c. a wind instrument used in a jazz band; especially trumpet  d. a usually electrical device that makes a noise like that of a ~  4. a source of strength  5. one of the equally disadvantageous alternatives presented by a dilemma  6. slang telephone  • ~ adjective  • ~ed adjective  • ~edness noun  • ~less adjective  • ~lessness noun  • ~like adjective HORN, CAPE  geographical name headland S Chile on Horn Island in Tierra del Fuego; southernmost point of South America, at 55°59?S