- a mirror or reflector, especially one of polished metal, as on a reflecting telescope.
- speculum metal.
- Surgery. an instrument for rendering a part accessible to observation, as by enlarging an orifice.
- Ornithology. a lustrous or specially colored area on the wings of certain birds.
Origin of speculum
1590–1600; < Latin: mirror, equivalent to spec(ere) to look, behold + -ulum instrumental suffix; see -ule
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for specula
I know of a gentleman who made a hundred of these specula with his own hands.The Vast Abyss
George Manville Fenn
For they had not only to design and make the specula, but also the mountings of the mirrors as well.Woman in Science
John Augustine Zahm
In the construction of reflecting telescopes, concave mirrors, or specula, are combined with a double convex lens.
The specula are made of speculum metal, which is a composition of certain proportions of copper and tin.
I do not know whether before that the Abb Rochon had thought of using the metal Platina for the specula telescope.The Writings of Thomas Jefferson, Vol. I (of 9)
- a mirror, esp one made of polished metal for use in a telescope, etc
- med an instrument for dilating a bodily cavity or passage to permit examination of its interior
- a patch of distinctive colour on the wing of a bird, esp in certain ducks
C16: from Latin: mirror, from specere to look at
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for specula
1590s, from Latin speculum, literally "mirror," from specere "to look at, view" (see scope (n.1)).
Online Etymology Dictionary, © 2010 Douglas Harper
- A mirror or polished metal plate that is used as a reflector in optical instruments.
- An instrument that is used to dilate the opening of a body cavity for medical examination.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.