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.

UROPYGIUM
U`ro*pyg"i*um, n. Etym: [NL., fr. Gr. (Anat.)

Defn: 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.

UROSACRAL
U`ro*sa"cral, a. Etym: [2d uro- + sacral.] (Anat.)

Defn: Of or pertaining to both the caudal and sacral parts of the vertebral column; as, the urosacral vertebræ of birds.

UROSCOPY
U*ros"co*py, n. Etym: [1st uro- + -scopy: cf. F. uroscopie.]

Defn: The diagnosis of diseases by inspection of urine. Sir T.
Browne.

UROSOME
U"ro*some, n. Etym: [2d uro- + -some body.] (Zoöl.)

Defn: The abdomen, or post-abdomen, of arthropods.

UROSTEGE
U"ro*stege, n. Etym: [2d uro- + Gr. (Zoöl.)