The coccyx (), commonly referred to as the tailbone, is the final segment of the human vertebral column. Comprising three to five separate or fused vertebrae (the coccygeal vertebrae) below the sacrum, it's attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between the sacrum and the coccyx. The term coccyx comes originally from the Greek language and means "cuckoo", referring to the curved shape of a cuckoo's beak when viewed fr… (More on Coccyx)