sartorius

sar·to·ri·us

noun \sär-ˈtōr-ē-əs\

plural -rii \-ē-ˌī\

Definition of SARTORIUS

: a muscle that arises from the anterior superior iliac spine, crosses the front of the thigh obliquely to insert on the upper part of the inner surface of the tibia, is the longest muscle in the human body, and acts to flex, abduct, and rotate the thigh laterally at the hip joint and to flex the leg at the knee joint and to rotate it medially in a way that enables one to sit with the heel of one leg on the knee of the opposite leg

Illustration of SARTORIUS