speculum

[Lat.=a mirror.] *I. Ord. Lang .: A mirror, a looking-gla . "A rough and colored object may serve for a speculum , to reflect the artificial rainbow."- Boyle: On Colors. II. Technically: 1. Astron . & Optics : A concave mirror of metal, especially one used as a reflector in a reflecting telescope. 2. Bot .: Prism a to carpus speculum . 3. Ornith.: A spot or patch, usually of brilliant colors, and metallic or iridescent, as on the wings of many of the Anatidae, the eyes in the peacock's tail, . 4. Surg.: An instrument for dilating certain pa ages of the body, in order to admit of examinations or acce of instruments for operation. Speculums are known by their construction, as bivalve, four-bladed valve, ., or by the part of the body to which they are applicable, as, anal, nasal, vaginal, .