“Vinegar cup” in Latin. The hip joint is made up of a deep rounded socket, the acetabulum, on the side of the pelvis and the round head of the femur (thigh bone). It is a very stable joint that is a compromise in structure which trades off the superior mobility, but less stability, of our shoulder joint for the task of supporting our body weight while walking. The Romans used a cup-like container for vinegar for the table and as a unit measure of volume. The same root, acetum, is found in acetic acid, the essential ingredient of vinegar. At the time, the primary source for vinegar was sour wine which is the exact meaning of “vinegar” in Latin!