fessier

Etymology
From.

Adjective

 * 1)  buttocks, gluteal
 * 2)  Specifically, of the buttocks' muscles
 * 1)  Specifically, of the buttocks' muscles

Noun

 * 1) the bottom as a whole
 * 2) One of several muscles in the buttocks
 * grand fessier ("gluteus maximus")
 * moyen fessier ("gluteus medius")
 * petit fessier ("gluteus minimus")