of or pertaining to the breast, or chest; as, the pectoral muscles.-relating to, or good for, diseases of the chest or lungs; as, a pectoral remedy.-having the breast conspicuously colored; as, the pectoral sandpiper.-a covering or protecting for the breast.-a breastplate, esp. that worn by the jewish high person.-a clasp or a cross worn on the breast.-a medicine for diseases of the chest organs, especially the lungs.