sternalis

noun
ster·​na·​lis | \ stər-ˈnā-ləs How to pronounce sternalis (audio) \
plural sternales\ -​(ˌ)lēz How to pronounce sternales (audio) \

Medical Definition of sternalis

: a muscle that sometimes occurs on the surface of the pectoralis major at its sternal end and that has its fibers running parallel to the sternum and perpendicular to the pectoralis major