genuflection (n.)

"act of bending the knee," especially in worship, early 15c., genu-fleccion, from Medieval Latin genuflectionem (nominative genuflexio) "bending of the knee," noun of action from past-participle stem of Late Latin genuflectere "genuflect," properly genu flectere "to bend the knee," from Latin genu "knee" (from PIE root *genu- (1) "knee; angle") + flectere "to bend" (see flexible).