The Collaborative International Dictionary
Urosteon
Urosteon \U*ros"te*on\, n.; pl. L. Urostea, E. Urosteons. [NL., fr. Gr. ? the tail + ? a bone.] (Anat.) A median ossification back of the lophosteon in the sternum of some birds.
Wiktionary
urosteon
n. (context anatomy English) A median ossification at the back of the lophosteon in the sternum of some birds.