'Uropygium' definitions:

Definition of 'uropygium'

(from WordNet)
noun
Posterior part of a bird's body from which the tail feathers grow

Definition of 'Uropygium'

From: GCIDE
  • Uropygium \U`ro*pyg"i*um\, n. [NL., fr. Gr. ?, (corrupted form) ?; ? the end of the os sacrum + ? rump.] (Anat.) The prominence at the posterior extremity of a bird's body, which supports the feathers of the tail; the rump; -- sometimes called pope's nose. [1913 Webster]