The pelvic girdle is a crucial part of the human skeleton. It provides a foundation for movement and stability for the lower extremity joints. There are several other terms used interchangeably with pelvic girdles. One of the most common is the hip bone or the coxal bone. The innominate bone, acetabulum and os coxae also describe this structure. The sacroiliac joint, which connects the sacrum and the ilium, is another synonym for the pelvic girdle. Additionally, the pelvic ring, composed of the pubic symphysis, ischium and ilium, is often used to describe this bony structure. These terms are essential to understand for medical professionals, athletes, and those with pelvic girdle pain.