| The American Heritage® Dictionary of the English Language: Fourth Edition. 2000. |
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| diopter |
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| SYLLABICATION: | di·op·ter |
| PRONUNCIATION: |  d - p t r |
| NOUN: | abbr. D. A unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length measured in meters. | | ETYMOLOGY: | Obsolete diopter, an instrument for measuring angles, from Latin dioptra, from Greek dioptr : dia-, dia- + optos, visible; see okw- in Appendix I. | | OTHER FORMS: | di·optral (-trl) —ADJECTIVE
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| The American Heritage® Dictionary of the English Language, Fourth Edition. Copyright © 2000 by Houghton Mifflin Company. Published by the Houghton Mifflin Company. All rights reserved. |
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