Uropygial
Pronunciation : U`ro*pyg"i*al
Part of Speech : a.
Etymology : [See Uropygium.] (Anat.)
Definition : Defn: Of or pertaining to the uropygium, or prominence at the base of the tail feathers, in birds. Uropygial gland, a peculiar sebaceous gland at the base of the tail feathers in most birds. It secretes an oily fluid which is spread over the feathers by preening.
Source : Webster's Unabridged Dictionary, 1913