speculum

 
Pronunciation: /ˈspɛkjʊləm/

noun (plural specula /-lə/)

  • 1 Medicine a metal instrument that is used to dilate an orifice or canal in the body to allow inspection.
  • 2 Ornithology a bright patch of plumage on the wings of certain birds, especially a strip of metallic sheen on the secondary flight feathers of many ducks.
  • 3a mirror or reflector of glass or metal, especially (formerly) a metallic mirror in a reflecting telescope.
  • short for speculum metal.

Origin:

late Middle English: from Latin, literally 'mirror', from specere 'to look'