- See i. (muscle).
* * *ili·a·cus i-'lī-ə-kəs n, pl ili·a·ci -ə-.sī a muscle of the iliac region of the abdomen that flexes the thigh or bends the pelvis and lumbar region forward, has its origin from the iliac fossa, iliac crest, the base of the sacrum, and adjoining parts, and is inserted into the outer side of the tendon of the psoas major, the capsule of the hip joint, and the lesser trochanter of the femur
* * *n.a flat triangular muscle situated in the area of the groin. This muscle acts in conjunction with the psoas muscle to flex the thigh.
Medical dictionary. 2011.