Definition of "lunation" [lu•na•tion]

• The time that elapses between successive new moons, averaging 29 days, 12 hours, 44 minutes; a lunar month. (noun)

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.

• "This process is called lunation, and it is akin to the Moon bowing slightly as it dances around us, watching us all the while."
• "As it had now been discovered that the exact length of the lunation is a little more than twenty-nine and a half days, it became necessary to abandon the alternate succession of full and deficient months; and, in order to preserve a more accurate correspondence between the civil month and the lunation, Meton divided the cycle into 125 full months of thirty days, and 110 deficient months of twenty-nine days each."
• "(In fact, you may need to look at the free online manual just to understand terms like "lunation" and "Astronomical Julian date.")"