li·​bra·​tion | \ lī-ˈbrā-shən How to pronounce libration (audio) \

Definition of libration

: an oscillation in the apparent aspect of a secondary body (such as a planet or a satellite) as seen from the primary object around which it revolves

Other Words from libration

librational \ lī-​ˈbrā-​shnəl How to pronounce librational (audio) , -​shə-​nᵊl \ adjective
libratory \ ˈlī-​brə-​ˌtȯr-​ē How to pronounce libratory (audio) \ adjective

First Known Use of libration

1667, in the meaning defined above

History and Etymology for libration

Latin libration-, libratio, from librare to balance, from libra scales

Keep scrolling for more

Learn More about libration

Time Traveler for libration

Time Traveler

The first known use of libration was in 1667

See more words from the same year

Statistics for libration

Cite this Entry

“Libration.” Dictionary, Merriam-Webster, Accessed 16 Feb. 2020.

More from Merriam-Webster on libration Encyclopedia article about libration

Comments on libration

What made you want to look up libration? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

More Confusing Words—Quiz

  • cats on impossible timber
  • The magician ______ moved the selected card to the top of the deck.
Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!