Definition of "synodic" []

• Of or relating to a synod; synodal. (adjective)
• Relating to the conjunction of celestial bodies, especially the interval between two successive conjunctions of a planet or the moon with the sun. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Venus thus overtakes and passes the earth once in five hundred and eighty-four days, or nearly two and a half of her own years, constituting what is called her synodic period of apparent revolution as seen from this globe."
• "The moon appears to go from one full moon to the next over a period of 29.53 days, known as a "synodic month.""
• "The moon revolves around Earth once with respect to the sun in about 29 1/2 days, a period known as a synodic month."