from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A triangular bone made up of five fused vertebrae and forming the posterior section of the pelvis.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A large triangular bone located at the base of the spine between the two hipbones of pelvis and formed from fused vertebrae.
from the GNU version of the Collaborative International Dictionary of English
- n. That part of the vertebral column which is directly connected with, or forms a part of, the pelvis.
from The Century Dictionary and Cyclopedia
- n. A compound bone resulting from the ankylosis of two or more vertebræ between the lumbar and the coccygeal region of the spine, mostly those which unite with the ilia; the os sacrum.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. wedge-shaped bone consisting of five fused vertebrae forming the posterior part of the pelvis; its base connects with the lowest lumbar vertebra and its tip with the coccyx
New Latin, from Late Latin (os) sacrum (translation of Greek hieron (osteon), sacred (bone)), neuter of Latin sacer, sacred; see sacred.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin ōs sacrum ("holy bone"), translation of Ancient Greek ἱερόν ὀστέον (hieron osteon). Called so either because supposedly sacrum was the part of an animal offered in sacrifice or because of the belief that the soul of the man resides there. (Wiktionary)