A way into a bizarre world (from the book Through the Looking-Glass, and What Alice Found There (1871) by Lewis Carroll.
A lookout place.
A bright, lustrous patch of colour found on the wings of ducks and some other birds, usually situated on the distal portions of the secondary quills, and much more brilliant in the adult male than in the female.
A mirror, especially one used in a telescope.
A medical instrument used during an examination to dilate an orifice.