Pygostyle \Py"go*style\, n. [Gr. pygh` the rump + ? a pillar.]
(Anat.)
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 vertebr[ae], and supports the uropigium.
[1913 Webster]