from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The plate supporting the tail-feathers in birds, formed from fused vertebrae.
from the GNU version of the Collaborative International Dictionary of English
- n. The plate of bone which forms the posterior end of the vertebral column in most birds; the plowshare bone; the vomer. It is formed by the union of a number of the last caudal vertebræ, and supports the uropigium.
from The Century Dictionary and Cyclopedia
- n. In ornithology, the vomer or plowshare bone of a bird's tail, consisting of a number of caudal vertebraæ ankylosed together for the support of the tail-feathers, and possessed by nearly all birds.
From pygo- + Ancient Greek στυλος (stulos, "column"). (Wiktionary)