u·ro·py·gi·al gland 
(yr′ə-pījē-əl, -pĭjē-)
(yr′ə-pījē-əl, -pĭjē-)n.
A large gland at the base of a bird's tail that secretes an oil used in preening. Also called oil gland.
- intro-
- introduce
- introducer
- introducible
- introduction
- introductorily
- introductory
- introgression
- introgressive
- introit
- introject
- introjection
- intromission
- intromissive
- intromit
- intromittent
- intromitter
- intron
- introrse
- introspect
- introspection
- introspectional
- introspective
- introspectively
- introversion