beltbelt1 /bɛlt/ ●●● noun [countable] 1 a band of leather or cloth that you wear around your waist2a circular band of material, such as rubber, that moves parts of a machine: the car’s fan belt3a large area of land that has particular qualities: America’s farm belt4have something under your belt to have already done something useful or important: At 25, she already has two novels under her belt. → seat belt