GIBBOUS, a term in Medicine, denoting any protuberance or convexity of the body, as a person hunch-ed or hump-backed.

Infants are much more subject to gibbosity than adults, and it oftener proceeds from external than internal causes. A fall, blow, or the like, frequently thus distorts the tender bones of infants. When it proceeds from an internal cause, it is generally from a relaxation of the ligaments that sustain the spine, or a caries of its vertebrae; though the spine may be inflected forward, and the vertebrae thrown out by a too strong and repeated action of the abdominal muscles. This, if not timely redressed, grows up and fixes as the bones harden, till in adults it is totally irretrievable: but when the disorder is recent, and the person young, there are hopes of a cure. The common method is by a machine of pasteboard, wood, or steel, which is made to press principally on the gibbous part; and this by long wearing may set all right. The surgeons, however, have a different instrument, which they call a cross, much more efficacious, though not quite so convenient in the wearing. By the use of this, the parts are always prevented from growing any worse, and are often cured. During the application of these assistances, the parts should be at times rubbed with Hungary water, spirit of lavender, or the like, and defended with a strengthening platter.