sacrum /sā″krəm, sak″rəm/ [L, sacer, sacred] , the large, triangular bone at the dorsal part of the pelvis, inserted like a wedge between the two hip bones. The base of the sacrum articulates with the last lumbar vertebra, and its apex articulates with the coccyx. Various muscles attach to its spinal crest. The sacrum is shorter and wider in women than in men. −sacral, adj.
