Medical Definition of hip 1 : the laterally projecting region of each side of the lower or posterior part of the mammalian trunk formed by the lateral parts of the pelvis and upper part of the femur together with the fleshy parts covering them. 2 : hip joint.
The hip is the area on each side of the pelvis. The pelvis bone is made up of 3 sections: Ilium. The broad, flaring portion of the pelvis.