What does tailbone mean?
A tailbone is the small bone at the base of the spine, anatomically called the coccyx. It is made of several fused vertebrae and is usually covered by skin and connective tissue rather than being a separate, freely movable bone. The term is especially common in descriptions of bruises, fractures, and other painful injuries caused by falling onto the buttocks. Although it is sometimes described as a vestigial tail, the coccyx still contributes to pelvic support, muscle attachment, and stability while sitting. In medical and anatomical writing, “coccyx” is the preferred term, while “tailbone” is the accessible everyday expression. A person may say that they have “broken” or “bruised” their tailbone, although the injury may involve the surrounding tissues as well as the bone itself.
nounThe tailbone, or coccyx, is the small, triangular bone at the lower end of the vertebral column, consisting of several fused vertebrae. It supports the pelvic floor and helps with sitting and balance.
- Anatomical name for the coccyx, the small bone at the base of the spine.
"She slipped on the icy path and badly bruised her tailbone."
"The doctor said the bruise on her tailbone would heal without treatment."
"A fall down the stairs caused him severe tailbone pain."
Usually used when referring to the tailbone of more than one person or animal, or in a general plural sense.
"The article explains how to relieve tailbone pain."
The tailbone is the body's vestigial remnant of a tail, yet it still helps support the pelvis and stabilize sitting.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does tailbone come from?
“Tailbone” is a compound formed in the early modern period from “tail” and “bone.” Its “tail” refers to the coccyx, which was understood in older anatomical terminology as a rudimentary or vestigial tail. “Tail” derives from Old English tæl, while “bone” comes from Old English bāne; both elements are inherited from Germanic languages.
Related word forms
How tailbone is actually used
In everyday medical contexts, “tailbone” is more common than the technical term “coccyx.”