• synonyms


adjective Optics.
  1. free from spherical aberration and coma.
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Origin of aplanatic

1785–95; a-6 + Greek planá(ein) to wander + -tic. See planet
Related formsap·la·nat·i·cal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for aplanatic

Historical Examples

  • A lens in which the spherical aberration is corrected is said to be aplanatic.

    An Elementary Text-book of the Microscope

    John William Griffith

  • Aplanatic triplets 64-68 can only be used on stands with rack and pinion adjustment.

British Dictionary definitions for aplanatic


  1. (of a lens or mirror) free from spherical aberration
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Derived Formsaplanatically, adverb

Word Origin

C18: from Greek aplanētos prevented from wandering, from a- 1 + planētos, from planaein to wander
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

aplanatic in Medicine


  1. Of or relating to an optical lens that is free from chromatic or spherical aberration.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.