Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Sacrum
Medically reviewed by Dr. Otari Nergadze, Neurosurgeon | Updated: January 2026
Sacrum: The large heavy bone at the base of the spine, which is made up of fused sacral vertebrae. The sacrum is located in the vertebral column, between the lumbar vertebrae and the coccyx. It is roughly triangular in shape and makes up the back wall of the pelvis. The female sacrum is wider and less curved than the male.
The name comes from the Latin "os sacrum" (holy bone). Why it was sacred is a matter of conjecture.