• synonyms


or syn·od·i·cal

[si-nod-ik or si-nod-i-kuh l]
See more synonyms on Thesaurus.com
  1. Astronomy. pertaining to a conjunction, or to two successive conjunctions of the same bodies.
  2. of or relating to a synod; synodal.

Origin of synodic

1555–65; < Late Latin synodicus < Greek synodikós. See synod, -ic
Related formssyn·od·i·cal·ly, adverbnon·syn·od·ic, adjectivenon·syn·od·i·cal, adjectivenon·syn·od·i·cal·ly, adverbsub·syn·od·ic, adjectivesub·syn·od·i·cal, adjectivesub·syn·od·i·cal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for synodic

Historical Examples

  • Why, because twenty-seven days is about the synodic period of solar rotation.

    Disturbing Sun

    Robert Shirley Richardson

  • The correlation with the synodic rotation of the Sun was practically perfect.

    Disturbing Sun

    Robert Shirley Richardson

  • They determined correctly within a small fraction the length of the synodic revolution of the moon.

  • Lunar Year, a period of 12 synodic lunar months, being about 354.5 days.

    The Nuttall Encyclopaedia

    Edited by Rev. James Wood

British Dictionary definitions for synodic


  1. relating to or involving a conjunction or two successive conjunctions of the same star, planet, or satellitethe synodic month
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

synodic in Science


  1. Relating to the conjunction of celestial bodies, especially to the interval between two successive conjunctions of a planet or the Moon with the Sun as viewed from Earth. For example, the new moon comes at the conjunction of the Moon with the Sun; the interval between successive new moons (the time it takes for the Moon to orbit the Earth and return to conjunction with the Sun) is the Moon's synodic period, also called a lunar month. Synodic time differs from sidereal time, which is measured in relation to the stars and is generally more appropriate to astronomical observation.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.