Definition of librate in English:

librate

Pronunciation /ˈlīˌbrāt/ /ˈlaɪˌbreɪt/

See synonyms for librate

intransitive verb

[no object]Astronomy
  • (of the moon) oscillate or seem to oscillate.

    • ‘the moon seemed to be librating twice as much as expected’

Origin

Early 17th century from Latin libratus, past participle of librare (see libration).