The cotyloid cavity, also known as the acetabulum, is a concave surface in the pelvis that articulates with the head of the femur to form the hip joint. There are a few synonyms for this anatomical term, including the hip socket, hip joint cavity, and acetabular fossa. Other less commonly used synonyms include the cotyloid fossa, cotyloid basin, and acetabular concavity. These terms are often used in medical and anatomical contexts to describe the structure and function of the hip joint. Understanding these synonyms can facilitate communication between healthcare professionals and their patients and help to promote accurate diagnosis and treatment of hip joint disorders.