noun
or pyr·i·for·mis ˌpirəˈfȯrmə̇s
( -es )
Etymology: piriformis, New Latin, alteration of pyriformis; pyriformis, New Latin, from Medieval Latin pyrum pear (alteration of Latin pirum ) + Latin -iformis -iform
: a muscle arising from the front of the sacrum, passing out of the pelvis through the greater sciatic foramen, and being inserted into the upper border of the great trochanter of the femur