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[lahy-brey-shuh n] /laɪˈbreɪ ʃən/
noun, Astronomy
a real or apparent oscillatory motion, especially of the moon.
1595-1605; < Latin lībrātiōn- (stem of lībrātiō) a balancing. See librate, -ion
Related forms
librational, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for libration
  • They took advantage of libration to make a stereogram.
British Dictionary definitions for libration


the act or an instance of oscillating
a real or apparent oscillation of the moon enabling approximately 59 per cent of the surface to be visible from the earth over a period of time
Derived Forms
librational, adjective
Word Origin
C17: from Latin librātus, from librāre to balance
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Encyclopedia Article for libration

in astronomy, an oscillation, apparent or real, of a satellite, such as the Moon, the surface of which may as a consequence be seen from different angles at different times from one point on its primary body

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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