1. Noun. (anatomy) A muscle that rotates the thigh laterally. ¹
¹ Source: wiktionary.com
1. Origin, margins of pelvic sacral foramina and greater sciatic notch of ilium; insertion, upper border of greater trochanter; action, rotates thigh laterally; nerve supply, nerve to piriformis (sciatic plexus). Synonym: musculus piriformis, musculus pyriformis, piriform muscle. (05 Mar 2000)