Of, pertaining to, or connected with the breast or chest; thoracic: as, a pectoral muscle, vessel, nerve, etc.; a pectornl limb.In entomology, pertaining to the pectus or lower surface of the thorax.n. Armor for the breast, excluding the throat and the lower part of the body.n. An ornament to be worn on the breast; especially, an ornament of an unfamiliar sort, or of a sort to which no special name is given: as an enameled pectoral.n. Eccles.: In the anc. Jewish ritual, a sacerdotal breastplate of richly colored and embroidered cloth, worn by the high priest.n. In the Roman Catholic Church, a square plate of gold, silver, or embroidery, either jeweled or enameled, formerly worn on the breast over the chasuble by bishops during the celebration of the mass.n. A pectoral cross.n. A food, a drink, or a drug supposed to be good for persons having weak lungs.n. A pectoral part or organ.Figuratively, proceeding from the breast, as of the heart; from the inner consciousness.