Dictionary
syn•sac•rum
Pronunciation: (sin-sak'rum, -sā'krum), [key]—
n.,
—pl. -sac•raPronunciation: (-sak'ru, -sā'kru). [key]
Ornith.
a dorsal ridge of bone in the pelvic region of birds, formed by the fusion of certain thoracic, lumbar, sacral, and caudal vertebrae.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.