What is the acetabelum?

Answer 1

The acetabelum is the hip socket. The "ball" joint of the hip fits into this socket so the leg can move properly.
I think you mean Acetabulum, and it is the socket of the hip joint.

Answer 2

The acetabulum is the socket-shaped structure in the pelvis bone where the head of the femur (thigh bone) sits to form the hip joint. It is essential for stability and movement of the hip joint.