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Webster 1913 Edition
Uropygial
Uˊro-pyg′i-al
,Adj.
[See
Uropygium
.] (Anat.)
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.