BELT, a flat strap of leather or other material, used as a girdle (q.v.), especially the cinctura gladii or sword-belt, the chief "ornament of investiture" of an earl or knight (O.Ger. balz) ; in machinery, a flexible strap passing round from one drum, pul ley or wheel to another, for the purpose of power-transmission (see BELTING). The word is applied to the belts of the planet Jupiter, to the armour-belt at the waterline of a warship, or to a narrow tract of country with special distinguishing character istics, such as the earthquake belt across a continent.