What does sacrum mean?
The sacrum is the triangular bone at the base of the spine, created when five vertebrae fuse together. It sits between the lumbar vertebrae and the coccyx, while also joining the two hip bones to form the back of the pelvis. In this structural role, the sacrum helps transfer the weight of the upper body to the pelvis and lower limbs and provides attachment points for muscles and ligaments. Anatomical and medical writing uses the term especially when discussing pelvic anatomy, lower-back or pelvic pain, and injuries such as sacral fractures. Its unusual history comes from the Latin sacrum, literally “sacred bone,” reflecting the ancient belief that this region of the body had special religious significance. The word is also the source of the adjective sacral, as in sacral vertebrae and sacral pain.
nounThe triangular bone at the base of the spine, formed by five fused vertebrae and connecting the vertebral column to the pelvic girdle. It also forms the posterior wall of the pelvis.
- The triangular bone at the base of the spine, formed by five fused vertebrae and forming the posterior part of the pelvis.
"The scan showed a fracture through the sacrum."
"Pain in the lower back may sometimes be referred from the sacrum."
"The sacrum supports the pelvic girdle and transmits weight from the upper body to the lower limbs."
The traditional anatomical plural is 'sacra'; 'sacrums' is also widely accepted.
"The scan revealed fractures on both sides of the sacra."
The sacrum was named for its ancient reputation as a sacred part of the body.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sacrum come from?
The English word sacrum comes from Latin sacrum, meaning “sacred” or “sacred bone.” The name arose from ancient beliefs that the sacrum was a particularly sacred part of the human body. Latin sacer, the source of sacrum, also underlies English words such as sacred, sacrifice, and sacrament.
Related word forms
How sacrum is actually used
In medical and anatomical contexts, the term is normally used in the singular. Its plural is usually 'sacra'; 'sacrums' is also accepted in modern usage.
Easily confused with sacrum
A sacrum is the bone itself, whereas sacral is an adjective meaning relating to the sacrum.