noun

sacrum

SAY-krum/ˈseɪkrəm/

The triangular bone at the base of the spine.

The sacrum connects the spine to both sides of the pelvis.

Accurate posterior anatomical pelvis with triangular sacrum centrally highlighted in muted coral between two pale ivory hip bones; five fused segments, paired foramina and coccyx below; no labels, no detached floating spine.

Etymology

The name means “sacred” in the phrase “sacred bone,” reportedly because this bone was offered in animal sacrifices. Some sources instead suggest a mistranslation of Greek describing it as the “strong bone.”

In context

Nuttall's Biology16:26

here we see the sacrum and coccyx the sacrum forms from five sacral vertebrae

Axial Skeleton Part 3

More examples

The scan shows a small fracture in her sacrum.
Five fused vertebrae form the adult sacrum.
The tailbone sits just below the sacrum.

Forms

sacrum · sacra · sacrums

sacral adjective — Relating to the sacrum or its region.