The coccygeal vertebra, also known as the tailbone, is a triangular bone located at the bottom end of the spinal column. There are several synonyms for the term coccygeal vertebra, including coccyx, tailbone, caudal vertebrae, and sacrum coccygeal region. The term coccyx is derived from the Greek word "kokkux" which means cuckoo as the bone is shaped like a cuckoo's beak. The caudal vertebrae refer to the series of small bones that form the tail of vertebrates. Furthermore, sacrum coccygeal region indicates the area where the sacrum and coccyx are located and are interconnected to form the pelvic girdle. The use of these synonyms can help provide a more detailed understanding of the structure's location and function in the body.