brow

Brow is a term with several related meanings. In everyday use it most commonly refers to the eyebrow region: the paired strips of hair located above the eye sockets, and the surrounding skin of the forehead. The word is also used to describe the bony margin just above each eye, the brow ridges formed by the frontal bone. In addition, brow can describe the edge or rim of a larger feature, for example the brow of a hill or the brow of a cliff.

Anatomy and function: The brows consist of hair, skin, and underlying muscles. The eyebrow hair grows in a curved shape that helps shade the eye from sunlight and shed sweat away from the eye. The brows also play a key role in facial expression, helping communicate emotions like surprise or concern through the movement of the corrugator and frontalis muscles. The brow ridge is part of the skull; in many adults it contributes to a pronounced forehead contour, though modern humans vary considerably.

Care, aesthetics, and health: People groom their brows through trimming, plucking, waxing, or shaping to alter appearance. Changes in brow hair can reflect aging, hormonal changes, or medical conditions such as alopecia areata or hypothyroidism. Diseases or trauma affecting the brow region can impact vision or sensation if nerves are involved. Cosmetic products or surgical procedures exist to restore or enhance the brow.