What is the coccyx commonly referred to in layman's terms?

The coccyx is commonly referred to as the tailbone in layman's terms because of its small, triangular shape at the very base of the vertebral column. This structure is a remnant of a tail from our evolutionary ancestors, which is why the term "tailbone" aptly describes its location and function.

The coccyx serves as an attachment site for various ligaments and muscles, contributing to pelvic support. Unlike the lower back, which is associated with the lumbar vertebrae and includes a different region of the spine, the term "tailbone" specifically highlights the coccyx's unique position at the end of the spine. The base of the skull refers to a completely different anatomical area and includes structures like the occipital bone, while the upper vertebrae pertain to cervical vertebrae located in the neck region. Therefore, "tailbone" is the most accurate and widely recognized term for the coccyx.