horn

Horn is a term used for several distinct objects and concepts in biology, music, and everyday life.

In biology, a horn typically refers to a hard, keratin-covered projection on the heads of certain animals, especially bovids such as cattle, goats, and antelopes. In true horns, a bony core extends from the skull and is enveloped by a thick keratin sheath. Horns grow continuously from the base and are usually permanent, not shed like antlers. They are commonly present in both sexes in many species and serve for defense, competition, and display. The keratin sheath can wear over time and may be removed or reduced through dehorning in livestock.

Rhino horns are a related but distinct structure. They are not true horns with a bone core; instead they consist of densely packed keratin fibers formed from the skin. Rhino horns grow from the snout and are targeted by poaching, contributing to conservation concerns for several species.

In music, a horn refers to the brass instrument known as the horn or French horn. The modern horn is a long, coiled tube with a bell and valves that change pitch. It evolved from signaling horns and natural horns, which had no valves. The instrument is typically pitched in F or B-flat and is played by buzzing the lips into a mouthpiece, with hand placement inside the bell used to modify tone and pitch.

Other uses include drinking horns, vessels made from animal horn, and symbolic or heraldic imagery. The term also appears in phrases and cultural contexts referring to strength, abundance, or signaling.