In researching the meaning of Sacrum I found this,
"The sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx (tailbone)."
"The name is derived from the Latin sacer, "sacred", a translation of the Greek hieron (osteon), meaning sacred or strong bone. This is supposedly because the sacrum was the part of an animal offered in sacrifice. In Slavic languages and in German this bone is called the "cross bone"
Eric Mead will like this, http://www.chiroweb.com/archives/16/22/03.htm