Merriam-Webster Collegiate Dictionary - pectoral

 I. noun  Date: 15th century  1. something worn on the breast  2. ~ muscle  II. adjective  Etymology: Middle French or Latin; Middle French, from Latin ~is, from pector-, pectus breast; akin to Tocharian A passam breasts, Old Irish ucht breast  Date: 1578  1. of, situated in or on, or worn on the chest  2. coming from the breast or heart as the seat of emotion