subpectoral
/ˌsʌbˈpɛkt(ə)rəl/ /ˌsʌbˈpɛkt(ə)r(ə)l/adjective
Chiefly Medicine and Anatomy. Situated beneath the chest or the pectoral muscles, or posterior to the thorax; of or relating to this part of the body.
Origin
Early 19th century. From sub- + pectoral.