synsacrum

[ sin-sak-ruh m, -sey-kruh m ]
/ sɪnˈsæk rəm, -ˈseɪ krəm /

noun, plural syn·sac·ra [sin-sak-ruh, -sey-kruh] /sɪnˈsæk rə, -ˈseɪ krə/. Ornithology.

a dorsal ridge of bone in the pelvic region of birds, formed by the fusion of certain thoracic, lumbar, sacral, and caudal vertebrae.

Origin of synsacrum

First recorded in 1900–05; syn- + sacrum

OTHER WORDS FROM synsacrum

syn·sa·cral, adjective pre·syn·sa·cral, adjective