• synonyms


[lon-ji-tood-n-l, -tyood-]
  1. of or relating to longitude or length: longitudinal measurement.
  2. extending in the direction of the length of a thing; running lengthwise: a thin, longitudinal stripe.
  3. Zoology. pertaining to or extending along the long axis of the body, or the direction from front to back, or head to tail.
  4. pertaining to a research design or survey in which the same subjects are observed repeatedly over a period of time.
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  1. a longitudinal framing member, as in the hull of a ship.
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Origin of longitudinal

1535–45; < Latin longitūdin- (stem of longitūdō; see longitude) + -al1
Related formslon·gi·tu·di·nal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for longitudinally

Historical Examples

  • Latitudinally they might traverse as circumstances required, but not longitudinally.


    Mayne Reid

  • The lateral planes of the prism are longitudinally striated.

  • The seats were arranged transversely instead of longitudinally.

  • (b.) from the Continent, in which it is rugged and longitudinally folded.

  • The spines are moderately slender and longitudinally striated.

    The Sea-beach at Ebb-tide

    Augusta Foote Arnold

British Dictionary definitions for longitudinally


  1. of or relating to longitude or length
  2. placed or extended lengthwaysCompare transverse (def. 1)
  3. psychol (of a study of behaviour) carried on over a protracted period of time
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Derived Formslongitudinally, adverb
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 longitudinally



1706, from Latin longitudo (see longitude) + -al (1).

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Online Etymology Dictionary, © 2010 Douglas Harper

longitudinally in Medicine


  1. Running in the direction of the long axis of the body or any of its parts.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.