horn

horn in zoology, one of a pair of structures projecting from the head of a hoofed animal, used chiefly as a weapon. In cattle, sheep, Old World antelopes, and related animals the horns are permanent and unbranched and are usually present in both sexes. They are composed of a sheath of keratin—a tough fibrous material derived from epithelial tissue—overlying a bony core projecting from the skull. In the deer family the branched structures, called antlers, are composed entirely of bone with no actual horn substance; they are usually present only in the male and are shed annually. The horns of the pronghorn have characteristics of both true horns and antlers. Rhinoceros horns are not true horn but greatly modified hair, derived entirely from the epidermis. Horns have long been used for many purposes, e.g., drinking cups, spoons, trumpets, containers for gunpowder, and combs. Carved pieces of horn have been found dating from prehistoric times. In art and religion horns symbolize power. The "horns of the altar" (Amos 3.14) symbolized divine protection. Hornlike protuberances appear on other animals, e.g., on the horned toad and the horned pout.

horn / hôrn/ • n. 1. a hard permanent outgrowth, often curved and pointed, found in pairs on the heads of cattle, sheep, goats, giraffes, etc., and consisting of a core of bone encased in keratinized skin. ∎  a woolly keratinized outgrowth, occurring singly or one behind another, on the snout of a rhinoceros. ∎  a deer's antler. ∎  a hornlike projection on the head of another animal, e.g., a snail's tentacle or the tuft of a horned owl. ∎  (horns) archaic a pair of horns as an emblem of a cuckold. 2. the substance of which horns are composed: powdered rhino horn. ∎  a receptacle or instrument made of horn, such as a drinking container or powder flask. 3. a thing resembling or compared to a horn in shape. ∎  a horn-shaped projection. ∎  a sharp promontory or mountain peak. ∎  a raised projection on the pommel of a Western saddle: slung from the horn of his saddle was a leather bag. ∎  (the Horn) Cape Horn. ∎  an arm or branch of a river or bay. ∎  the extremity of the moon or other crescent. ∎ Brit., vulgar slang an erect penis. 4. a wind instrument, conical in shape or wound into a spiral, originally made from an animal horn (now typically brass) and played by lip vibration. ∎ short for French horn. 5. an instrument sounding a warning or other signal: a car horn. • v. [tr.] (of an animal) butt or gore with the horns. PHRASES: blow (or toot) one's own horn inf. talk boastfully about oneself or one's achievements. draw (or pull) in one's horns become less assertive or ambitious. on the horn inf. on the telephone: she got on the horn to complain. on the horns of a dilemma faced with a decision involving equally unfavorable alternatives.PHRASAL VERBS: horn in inf. intrude; interfere.DERIVATIVES: horn·ist / -ist/ n. (in sense 4). horn·less adj. horn·like / -ˌlīk/ adj.

horn bony excrescence (often curved and pointed) on the head of cattle, etc.; instrument made from or in imitation of this OE.; pointed projection XIII; substance of it XV. OE. horn m., corr. to OS. horn m., OHG., ON. horn n. (Du. hoorn, G. horn), Goth. haurn n. :- Gmc. *χurnaz, -am, rel. to L. cornū, Skr. śŕṅga-, and further to Gr. Kéras; cf. HART.
Hence hornblende XVIII. — G. hornbook ABC tablet covered with horn. XVI.