Related Searches
on Ask.com
dioptre - 2 dictionary results
di⋅op⋅ter
[dahy-op-ter] 
–noun
| 1. | Optics. a unit of measure of the refractive power of a lens, having the dimension of the reciprocal of length and a unit equal to the reciprocal of one meter. Abbreviation: D |
| 2. | an instrument, invented by Hipparchus, to measure the apparent diameter of the sun or moon or to estimate the size or elevation of distant objects. |
Also, especially British, di⋅op⋅tre.
Origin:
1585–95; < L dioptra < Gk: instrument for measuring height or levels, equiv. to di- di- 3 + op- (for ópsesthai to see) + -tra n. suffix of means
1585–95; < L dioptra < Gk: instrument for measuring height or levels, equiv. to di- di- 3 + op- (for ópsesthai to see) + -tra n. suffix of means
Related forms:
di⋅op⋅tral, adjective
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
|
Link To dioptre
Dioptre
Di*op"tre\, n. [F. See 2d Dioptric.] (Optics) A unit employed by oculists in numbering glasses according to the metric system; a refractive power equal to that of a glass whose principal focal distance is one meter.
Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.
Cite This Source
Cite This Source
Copyright © 2009, Dictionary.com, LLC. All rights reserved.
