尾脂的
Uropygial \U`ro*pyg"i*al\, a. [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.